


歩むもののない道: Butterfly

by Cici_Nota



Category: Kamen Rider Drive
Genre: Alternate Universe - Canon Divergence, Anger, Canon-Typical Violence, Communication Failure, Dysfunctional Relationships, F/M, Hurt No Comfort, Internalized Homophobia, It Gets Worse Before It Gets Better, M/M, Slow Burn
Language: English
Status: In-Progress
Published: 2019-12-15
Updated: 2020-03-21
Packaged: 2021-02-25 05:00:44
Rating: Mature
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 8
Words: 65,756
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/21810466
Author URL: https://archiveofourown.org/users/Cici_Nota/pseuds/Cici_Nota
Summary: The sibling who finds Mashin Chaser dying in the rain is Shijima Go; despite his hatred and his desire to see the Roidmudes utterly destroyed, he can neither kill this Roidmude nor let it die.Chaos ensues.[1/20/21 - i continue to maintain that the hiatus is temporary]
Relationships: Chase | Mashin Chaser/Shijima Gou, Shijima Kiriko/Tomari Shinnosuke (background)
Comments: 17
Kudos: 39





	1. Non-Linear Impact

**Author's Note:**

> I saw a doujinshi cover with this premise on Yahoo!Japan once and have forever regretted not paying someone to buy it. I'm fairly sure that whatever was in that book bears no resemblance to what's getting published here, haha, but the concept wouldn't leave me alone, so here we are. Initial dialogue is lifted from Drive Ep22, after which the narrative takes a hard left into partially charted and then uncharted territory. 
> 
> The rough draft is currently incomplete; regular posting commences when the rough draft and the first round of editing have been finished. January seems likely. Tags will be updated as appropriate.

“Do you think his Core is gone?”

“You’ve finally defeated him, Shinnosuke.”

“Chaser, if you’d been an ally – how much happier we all would have been.” Tomari Shinnosuke’s face was hidden behind his armor’s visor, but the defeated slump of his shoulders and the wistful tone of his voice were unmistakable. Kiriko’s mouth twisted in the way that meant she was fighting back tears, and even Krim’s artificial face was carefully blank.

Suppressing a wince, Shijima Go edged away from the scene before someone found him lurking where he wasn’t supposed to be. _It would end up being_ _Kiriko_ , his mind supplied. Go’s imagination was all too willing to picture what his sister would do to him if she found him haunting the edge of a fight he’d deliberately turned over to someone else, as if his battered and exhausted body could have taken the strain of another transformation so soon.

How Kiriko would react to what she kept calling reckless behavior – and it wasn’t reckless, not by Go’s standards, he’d gotten used to the strain of using the Mach Driver and he’d adapt to the added stress of Shift Dead Heat, too – wasn’t the point. The point was that another Roidmude was dead and yet his sister and his rival were _upset_ about it.

“Just because it looks human,” Go muttered, sneaking between buildings until he could get to the side street where he’d parked his bike, hopefully far enough away that no one would notice the distinctive sound of its engine catching. Any other day, he would have taken pride in the flashy whine the Ride Macher put out; today, he was trying not to get caught, and stealthy was not an often-used skill. Which was also not the point. “Looks human,” Go said, swinging a leg over the seat and flinching as it felt like something inside tugged the wrong way. “Looks human,” he said a third time, through gritted teeth, “and has a pretty face, and they’re sad that the monster is gone.”

At least he knew the Roidmudes had decreased by one more, given the magnitude of the explosion. He hadn’t seen Chaser’s core disintegrate, but the flames had been pretty definitive, and he felt safe crossing the 109th monster off his list.

“There aren’t even supposed to be a hundred and nine,” he muttered, sliding the bike in and out through traffic until he reached Kiriko’s apartment. She’d told him to go home, but he was pretty sure she didn’t expect him to listen. Even so, it wasn’t like he could go back to the Drive Pit where any member of the Special Investigation Unit would have told his sister that he’d gone and come back and given him away. Chase’s pretty human face swam in his mind’s eye with its purple eyes and dark hair, and Go shook his head. “You’re an anomaly,” he told it. “Only supposed to be a hundred and eight. You weren’t even supposed to exist.”

Kiriko’s apartment building was tall enough to block out the late afternoon sun across a good chunk of the street, and Go suddenly didn’t want to go inside. He turned his helmet over and over in his hands, the blankness of the windows in front of him almost mocking. He didn’t want to go home, either, or even back to the Drive Pit. There were too many Roidmudes, too many abominations, and even if Shinnosuke had destroyed Mashin Chaser with the new Drive Type Formula armor, that still left Heart, and Medic, and dozens of lower-caliber mooks.

Pain spiked behind Go’s eyeballs, reminding him of why he wasn’t out chasing said abominations, but he still didn’t want to go inside. If it was warm enough for his sister to run around in a skirt and heels and no jacket, Go decided, it was warm enough to go walking. His sister had other plans, sneaking up behind him without so much as a hint of warning.

“So this is where you went,” she said.

Go suppressed a guilty start and turned around. He hadn’t even made it off the bike. Kiriko was eying him up and down, face tight with worry and disapproval. “I was just leaving,” he said.

“Go,” she said, and hesitated.

“Did he do it?” Go asked softly, and hated the way Kiriko’s face saddened at the question. She took a deep breath and squared her shoulders almost imperceptibly.

“Chaser has been destroyed,” Kiriko said, and Go nodded in acknowledgement.

“Tell – tell Shin thank you,” he said, and his sister’s gaze snapped toward him. “I’m going to, um.” He gestured aimlessly. “I’m going to get going. Take care, okay?”

“You want a ride?” Kiriko glanced at the western sky, starting to fill with clouds.

It would be a spectacular sunset, Go thought idly, if nothing else changed and thought it was maybe odd, that so cloudless a day would turn towards a storm so quickly. _Sometimes that’s how spring goes_ came unbidden, and he remembered that Kiriko had asked him a question. “No,” he said, just a little too late to be natural. “It’s not far, remember?”

“I remember,” Kiriko said tartly. “I also remember that you fainted after your last fight.”

“I did not,” Go retorted.

“Uh huh.” Kiriko eyed him speculatively. “Whatever you would call it, I caught you just before you split your head open on the ground. You sure you’re okay to drive back?”

“Fine,” he told her sourly, and then hated the way he’d probably made her feel worse. “I’m just.” He jammed his helmet back on and took off, leaving a cloud of dust in his wake. “I’ll kill them all,” he promised her when he was sure she couldn’t hear. “Before you know our father created them, and you won’t have to feel as guilty as I do.”

The guilt laced through everything else crawled under his skin and burned, and there was no way he was going to go home and sit still. Go swung down another street the moment he was out of his sister’s sight, picking directions he thought were random until he realized he had driven in the direction of Chaser’s last fight against Drive.

“Why am I here,” he muttered.

The clouds had rolled in, during his aimless drive. Caught up in city traffic, he hadn’t noticed it getting almost completely dark until he pulled the Ride Macher into an alleyway and shut off the engine. As if on cue, rain sputtered and started to fall.

“Oh, come on.”

If Go had been wearing the Mach armor, the rain wouldn’t have bothered him. He fingered the Signal Bike in his pocket and thought about it, but even if he didn’t do anything in the armor, just putting it on was draining enough. The last thing he needed was to give Kiriko any more reason to look at him askance. Between the Roidmudes in Tokyo and the years he’d spent in the United States driving a wedge between them, it was hard enough already.

“No reason to make her hate me any more than she already does, right?” he said ruefully to the Signal Bike in his palm. It didn’t answer, and he stuffed it back in his pocket.

The influx of clouds further darkened the sky, the rain slowly increasing to a steady downpour until Go was soaked to the skin. He cursed at the weather in English, then in Japanese, and then in English again for good measure. The rain refused to stop falling, instead coming down even harder as if in retaliation.

“You’re an asshole,” Go said to the sky, and there was an overpass not far ahead. He pulled the Ride Macher under it, wondering absently how it could be even colder in the relative dry, and thought about just waiting for the rain to stop.

Movement caught the corner of his eye, and Go turned to face it. In his experience, unexpected flashes of motion were never innocuous; more often than not, they belonged to Roidmudes bent on destruction, instead of unnoticed traffic or other pedestrians. The view in front of him refused to fall together into anything coherent for a long moment, until finally resolving itself into a pair of trembling legs. Go inched forward, prepared now to have come across a drunk salaryman – _in purple pants_? – before revising his estimate to _student._

The face attached to the body wearing the pants shouldn’t have come as a shock, and yet Go felt the bottom drop out of his stomach. Sprawled on the coping between two pillars was the very Roidmude Shinnosuke had allegedly destroyed, eyes half-lidded and pretty face twisted into a grimace as it clutched at its chest.

“Chase,” Go snarled, reaching for the Signal Bike. The stress of transformation was irrelevant; Chase was an abomination and had somehow escaped destruction. “I saw you die,” he said, still straddling the bike. The belt went around his hips, Signal Bike shoved into the slot. It took him three tries, hands stiff with cold, but it went. “If it didn’t take that time, I’ll make sure it takes this time.”

The Roidmude didn’t react, curling in on itself and panting harshly. If it had been human, Go would have said it was in pain. If it had been human, he would have felt sympathy. Hand on the Signal Bike, ready to initiate the transformation, Go hesitated. In his moment of hesitation, the Roidmude went limp and tumbled off the coping to lie in a heap on the pavement.

“Dammit,” Go said, pouring all of his anger into the word. He _knew_ Chase was a monster, an enemy of humanity, that his very nature as a Roidmude made him a dangerous creature that couldn’t be trusted, but all he could see in front of him was a man not much older than he himself was, unconscious and in need of help. “You don’t need my help,” he said viciously, parking his bike to block the street and turning on its hazard lights. “You should be dead.”

Chase groaned, eyes moving under the lids. It was bleeding sluggishly down the right side of its face, even the red of its blood a filthy inhuman lie, and Go’s own words came back to haunt him. _Proto-Drive was the one who saved your life_ , he’d said to his sister, flinging the words at her like weapons. Shin had wanted to work with this Roidmude, reason with it and restore its memory to what it had apparently been on the night of the Global Freeze, and it was one of his few lapses in judgment.

“Pretty fucking big lapse,” Go muttered under his breath, crouching beside Chase. He turned the Roidmude’s head roughly to one side, feeling the softness of its skin beneath his thumb. A pulse beat, rabbit-quick and off-rhythm, and Go slammed his hand on the ground in frustration. “Why do you even feel human?” he spat, and stood to leave.

If he left it alone, maybe the Roidmude would die anyway; Go didn’t have the stomach to murder a defenseless opponent, even if that opponent was a murdering abomination bent on destroying humanity. It wouldn’t be _right_.

Go cursed again and kicked the concrete of the coping with the ball of his foot. The shock traveled up his leg, nearly knocking him backwards before he regained his balance, and he stared at the unconscious Roidmude in resentment. “That was _your_ fault,” he said, but he couldn’t just abandon it either; it would either be tantamount to murder or allowing a valuable resource to return to the enemy. “Fuck, fuck, fuck, fuck.”

The Roidmude was a dead weight – _not dead enough_ , Go thought – when he tried to manhandle it onto the back of his bike somehow and take it somewhere. He’d figure that out when and if he could get Chase off the street, the process made difficult by Chase absolutely refusing to help. The Roidmude just moaned pitifully, and it made Go’s stomach turn. He propped it up against the coping, pulled out his cell phone, and gave in to the inevitable.

The daiko driver tasked with driving the Ride Macher faced the prospect of riding a motorcycle in a downpour with apparently infinite professionalism, stowing Go’s helmet in its proper spot without being asked and putting his own on. He even helped Go lift Chase into the back seat of the taxi, seeming to accept without question Go’s half-hearted explanation of too much to drink despite the absolute lack of proximity to anything resembling a restaurant or a bar.

Once in the taxi, the second driver was just as blankly courteous, his very blandness setting Go’s teeth on edge. It was insulting, that’s what it was, the stiff mask hiding disapproval as the driver asked for a destination.

“Um.” Go hadn’t managed to get that far, in all the time he’d spent waiting for the taxi to show up. “Fuck it,” he muttered in English, and somehow the driver’s face flattened even further. Go gave him the address of his apartment; Kiriko probably wouldn’t show up unannounced and he didn’t think Shin even knew where he lived. It was the safest place to stash the Roidmude until Go could decide what to do with it, even if every instinct he had was screaming at him not to let such a dangerous freak into his home.

_It’s not like it’s home_ , he thought, as the taxi swung onto the road. He could see the Ride Macher out of the corner of his eye, the daiko driver apparently competent enough to drive it in the rain. _It’s just somewhere I sleep, for now._

For the moment, Go had a potentially valuable hostage. He wouldn’t have wagered on Heart – or any other Roidmude – letting him use Chase as leverage, but it could be possible to get information out of it. He nodded; that would be the plan, then, and when the Roidmude had healed enough to put up a fight, Go would kill it.


	2. Deterministic Chaos

The side of Shinnosuke’s neck still twinged a little, despite Trailer-Hou’s protective qualities. It took time to heal damaged tissue, and Shinnosuke didn’t feel comfortable being at less than hundred percent. The Roidmudes were unpredictable, and just because he wasn’t always on high alert didn’t mean he shouldn’t be _capable_ of responding to an emergency.

The streaks of water hitting the reflective window glass were surprising, until the sound of rain eased back into Shinnosuke’s conscious memory. He’d been hearing it on and off for at least the past hour, and he should have gone home long ago. It was easier to get his work done in the evening, though, after the rest of the team left; the routine and the mundane aspects of working as a police officer, and all of the ridiculous paperwork that Shinnosuke swore spawned more barely distinguishable copies of itself every time he turned his back.

“I don’t even want to look at the clock.” Shinnosuke couldn’t help himself; the analogue clock lurking just out of his direct line of sight told him it was already significantly past eight, and his stomach growled. “Okay, okay, we’re leaving.”

Driving home in the rain wasn’t ideal, but Shinnosuke reasoned with himself that it was driving, and not walking, and that there would be a roof over his head made the wet streets seem not that bad. He put a hand to the side of his neck again, as the motion to glance toward the clock triggered another ache, and Shift Formula disappearing around a corner gave him a thought. Mad Doctor could probably do something about soft tissue damage, and it wasn’t as though Shinnosuke would be misusing resources, not if he was making sure he was fully ready to respond to Roidmude activity.

The main lights were off in the maze of hallways leading to the Drive Pit, but Shinnosuke knew the way there well enough that he could have navigated his way there blindfolded. He somehow still tripped on at least one piece of furniture that he swore hadn’t been there that morning, despite the undisturbed layer of thick dust on its surface. He slid the door to the Drive Pit open with more force than necessary, white light spilling out into the hallway.

Shinnosuke blinked. The lights should have been off in the Drive Pit as well, at this hour, but it wasn’t empty. Go was standing in the center of the room, blinking up at the open door with one hand in his pocket and a vaguely guilty expression on his face. “Shin,” he said.

“You’re here late.” Shinnosuke jogged down the stairs. “What’s going on?”

Go shrugged nonchalantly, pulling a used tissue out of his pocket. “I got bored,” he said. “Hey, where’s the trash can?”

“Where it’s always been,” Shinnosuke told him, and pointed under one of the desks.

“How is there only one, in this entire setup?” Go dropped his tissue and rubbed at his nose with his other hand. His hair and clothes were damp, Shinnosuke suddenly realized.

“Were you out in the rain?”

“So what if I was?” Instantly defensive, Go hunched his shoulders slightly and started edging toward the door.

“Your sister will kill you if you catch a cold. Which you already probably did. Did you bike here?” The guilty expression deepened and Go looked at the floor off to the side. Shinnosuke sighed. “Is it still raining?”

“Not as much.” The Ride Macher was near the door, Shinnosuke now saw, streaked with water despite Go’s words.

“Come on,” he said. “I’ll give you a ride home, and you can pick up the bike tomorrow.”

“Then I have to pick up the bike tomorrow,” Go objected. “Really, it’s better than it was.”

A rolling boom of thunder, audible even underground, belied his words, and Go shivered slightly. Shinnosuke resisted the urge to bury his face in his hands and wondered how, exactly, he had turned into the responsible one. “If you’re still not feeling well tomorrow, maybe we can get one of the students to bring the bike,” he said, and watched as a look of horror crossed Go’s face.

“No, no, it’s fine. I’ll just drive it back now.”

Opening the gates in the ceiling in preparation to lift both Tridoron and the Ride Macher back out of the Drive Pit was an argument in Shinnosuke’s favor; despite the opening coming out underneath an overpass, raindrops still gusted downwards and the sound of water hitting the ground overhead was almost deafening. Shinnosuke raised an eyebrow. Go, in a rare display of good sense, stalked over to the passenger side of Tridoron and climbed in with ill grace.

Shinnosuke forbore to comment on the drive back to Go’s apartment, although he realized as soon as he put the car in gear that he didn’t know where it was. Go hesitated before rattling off an address, and Shinnosuke thought perhaps that was the source of his reluctance; Go insisted on labeling Shinnosuke a rival rather than a teammate, and so probably did not want said rival to know where he lived.

The building itself was perfectly normal; four stories, the first taken up by a parking lot with numbered slots, and stairs to either side leading to the five-unit wide residential floors painted in what Shinnosuke thought was a not particularly attractive shade of seafoam green. Go grimaced and climbed out of the car almost before it had come to a complete stop. “Thanks for the lift,” he said, already soaked by the downpour, and ran for the stairs before Shinnosuke could respond.

The stairs were half-exposed to the driving rain, and Shinnosuke watched Go climb up to the fourth floor and open the center door before taking his foot off the brake and easing Tridoron back down the street. He hadn’t even had a chance to put the car in park, and now he didn’t know where he was. Mr. Belt was no help at all, apparently napping on the dashboard, and Shinnosuke muttered under his breath as he looked up the route home. It wasn’t until he got there, parking Tridoron in its usual spot and collecting Mr. Belt, that he remembered he’d gone to the Drive Pit in the first place looking for Mad Doctor.

“Ugh,” he said out loud, and Mr. Belt blinked.

“Is something wrong?”

Shinnosuke weighed the effort it would take go to back to the Drive Pit and find Mad Doctor; the Shift Cars were vulnerable in weather like this, and were only supposed to be called in an emergency anyway. “No,” he said finally. His neck wasn’t that sore, and would probably fix itself overnight, if he thought about it optimistically enough. “Just the weather.”

“I always liked the rain,” Mr. Belt said wistfully, and Shinnosuke closed his mouth firmly on the next complaint he’d wanted to make before heading inside.

* * *

Go shook the water out of his hair and closed the apartment door tightly behind him before pulling Mad Doctor out of his jacket pocket. “Stupid,” he muttered to himself. He could have called Mad Doctor, except that then the message would have gone out to all of the Shift Cars and probably alerted Shinnosuke, who would have wanted to know what Go was doing with said Shift Car. Having Shinnosuke nearly catch him in the act of making off with it wasn’t much better, but at least he’d accepted Go’s explanation of boredom at face value.

The blinds in the bedroom window overlooking the walkway in front of the apartment were firmly closed, even though the Roidmude wasn’t in the bedroom. That door was closed, too, but Go opened it just to make sure the Roidmude hadn’t snuck inside while he wasn’t around to stop it before continuing toward the kitchen door at the end of the hall. Paranoia made him check the small toilet on one side of the hall and the bathing room on the other, before he reached the kitchen door. They were both empty and he rolled his eyes.

The blinds covering the balcony doors on the opposite side of the kitchen were tightly shut as well, secured with a pair of clothespins just in case, and the Roidmude hadn’t made its way into the kitchen either. Go took a deep breath, running his fingers over Mad Doctor’s contours, and looked at the closed door on his left. He opened it with a sense of trepidation, feeling the warmer air flow outwards.

The living room was exactly how Go had left it – blinds pinned shut, kotatsu shoved up against the balcony doors, and the Roidmude sprawled on the kotatsu quilt in a bid to keep at least some of the water off the tatami mats covering the floor. The electric heater hadn’t been overturned and hadn’t set anything on fire in Go’s absence, and he glared at it for a moment. It wasn’t pointed directly at the Roidmude, and it had done a solid job of heating the one room.

“Explain to me again why we can’t have central heat,” he said to it, and then he realized he was stalling. “Mad Doctor,” he said, and the little Shift Car vibrated in his palm. “Use the Break Gunner?”

Since the Shift Car had to be inserted into a compatible piece of equipment to work, and since Go had discovered the Break Gunner hooked to the back of the Roidmude’s belt when he’d loaded it into the daiko taxi, it made sense. He didn’t want to touch the Break Gunner, though. He didn’t want to touch the Roidmude, didn’t want to know if the rest of its human-looking skin felt as soft as the skin at its throat. He definitely didn’t want to –

“This is getting out of hand,” Go said out loud, forcibly removing himself from his train of thought before it could go somewhere he absolutely did not want to see. He made himself pick up the Break Gunner, dropped carelessly on the kotatsu, and inserted Mad Doctor into it. “Are you even still alive?” he said to the Roidmude, but it didn’t so much as twitch when he pushed it onto its back and dragged it closer to the door.

The tatami under the quilt wasn’t damp, Go was glad to see, and he ran a hand over it just to make sure he hadn’t ruined the floor. _Quit stalling_ , he told himself, and looked closer at the Roidmude. The scrape down the side of its face had stopped bleeding and started to bruise, another mark on the opposite side of its forehead, and its eyes remained stubbornly shut. It was completely limp, its mockery of human skin pale and bloodless, but Go could see it breathing.

“Why shouldn’t I just let you _die_ ,” he said. It would be so easy. All he would have to do was nothing, and he would be one hated machine closer to making amends for the sins of his father, Kiriko’s voice echoed in his memory again. ProtoDrive had saved her life, on the night of the Global Freeze, and this thing in front of him had been ProtoDrive once. It had been constructed to help humanity, and it was a Roidmude. “Beating you fair and square in a fight would be one thing, but it would be wrong to kill you while you’re defenseless,” Go said, and felt something inside himself ease.

 _That’s what makes us better than them_ , he thought, calmer now, and put both hands on the Break Gunner. _I have the quality of mercy, and most of them are just murderers._

“Mad Doctor,” he said again. “This is going to be our little secret, okay? So please fix – fix Mashin Chaser.”

Go slammed the Break Gunner to the center of the Roidmude’s chest, where he’d seen it activate its transformation, and the sound of the Shift Car’s sirens filled his ears. The Roidmude’s eyes shot open, burning a poisonous shade of purple, and it went rigid. Its back arched, fingernails scrabbling uselessly along the tatami, and Go held the Break Gunner in place until the Shift Car finally quieted. The Roidmude’s eyes rolled up and it collapsed, paler than before.

Go nudged the Roidmude with his toe, but it didn’t respond. It seemed to be breathing more easily, though, and the damage to its face was nearly gone. He looked at Mad Doctor. “So do you need to be recharged or what?” he asked, but his Signal Bikes didn’t need it. Maybe the Shift Car didn’t need it either. “We’ll just do this again tomorrow, then.”

The Break Gunner got stuffed under Go’s mattress, just in case, but he felt fairly confident about leaving the Roidmude in the living room with the heater set on low. It seemed unlikely to set the building on fire at that level, and besides, if he let the Roidmude freeze to death, it would undo all of Go’s hard work. Even if the Roidmude was unlikely to freeze to death inside an insulated building.

It took two days for the Roidmude to so much as open its eyes, as far as Go could tell. He set Mad Doctor at it again the following evening, and focused his energy on getting stronger. And paying rent. Shinnosuke might have gotten a regular paycheck for being a Kamen Rider – okay, not technically, Go thought, but it was close enough – but most people didn’t have get paid for being a superhero. If, he admitted, by most people he meant himself. Either way, it was enough to keep him out of his apartment for most of the day and only returning when it got dark.

Day three of the Roidmude in Go’s living room – and Go kept dragging it around, trying to keep the floor from growing mold, and it remained stubbornly unconscious the entire time – and he was starting to think it was an exercise in futility. He’d made a point of returning at noon to see if changing the time he set Mad Doctor to trying to repair the Roidmude’s damage would make a difference; the Roidmude only responded when Mad Doctor was pouring energy into it, and Go was beginning to wonder if he could sidestep the ethical implications of murder if the Roidmude was a vegetable.

“I could always just ask Shin what to do with you,” he said to it, swiping Mad Doctor out of the storage closet and inserting the Shift Car into the Break Gunner. “Okay, time to do your thing.”

The Break Gunner swung downwards and met resistance in the form of a sudden cobra-quick grip on Go’s wrist, Mad Doctor sparking unpleasantly. Go dropped the Break Gunner in shock and Mad Doctor skittered away before the Break Gunner dented the tatami. Go looked unwillingly from the broken fibers to the Roidmude, knowing that it would be staring at him with its unearthly eyes.

It was.

“Why?” the Roidmude asked, voice rough with disuse.

“Why what?” Go yanked his hand free easily; the Roidmude was quick, but it hadn’t regained its strength, and its grip gave way without much resistance.

“Why did you save me?” it said quietly. It was prettier with its eyes open and an approximation of confusion painted across its human face, and Go frowned.

“You think I’m going to kill something helpless?” he spat at it. “Like I’m one of _you_?”

The Roidmude flinched at that, just enough that Go felt guilty, before its expressionless mask returned. “I am in your debt, Shijima Go.”

“You’re not in my _debt_.” Go shoved himself away from the Roidmude, scrambling across the floor until he was out of arm’s reach. “I don’t _want_ anything from you.”

The Roidmude tilted its head to the side to watch him, but made no move to rise. “You repaired me,” it said, as if testing the words.

“I – look, you wouldn’t understand. You’re not human. You’re just a – a machine that looks like us, and you wouldn’t _get_ it.” Go stood up, wiping his palms on his pants. “Don’t think this means I don’t want you dead, either.”

“I don’t understand,” the Roidmude said, eyes still fixed on Go’s face. It was eerie. Go wasn’t even sure it was blinking. “If you want me dead, then why did you help me?”

“I told you,” Go said, all of his misgivings pouring back and lodging in his chest like a stone. “You wouldn’t get it. Don’t say anything else,” he added when the Roidmude opened its mouth again.

The Roidmude looked unhappy, Go thought, and he shoved the thought away. It was a machine; it didn’t have emotions. The ones that did copied their personalities from the humans they corrupted and killed, and nothing they felt was real. Go made the gesture for _I’m watching you_ and left the living room, closing the door behind himself. He had barely taken a step away when he turned back to open it slightly.

“And don’t leave this room.” He could only see the top of the Roidmude’s head from where it was all but wedged into the corner next to the door, feet pointed at the double glass doors leading to the balcony, but he could tell that it nodded in answer, and this time he left the door closed.

Mad Doctor was on the kitchen table, and Go stared at it for a minute. If the Roidmude was awake, Mad Doctor could go back to the Drive Pit, he thought, but if he tried to return it now, it would be noticed. If he just sent it back, its return would be noticed, and questions would be asked. Go left it where it was and headed for his favorite gym. He hadn’t been the one to defeat Chaser, and if Shin was going to show sympathy for a Roidmude, Go couldn’t depend on him to defeat them all. Go had to be stronger, had to get rid of them before Kiriko learned the truth.

Barely enough time passed for Go to warm up before Kiriko came bursting through the door as if he’d summoned her, Shin hard on her heels. Go saw them before they found him, the dramatic swing of the door sending a warning breeze through the edges of the room just before it crashed into the wall, and Go wondered briefly if he had time to hide.

“Go!”

Too late. Go pretended his set hadn’t been interrupted and restarted the rhythm.

“I thought you’d be here.” Kiriko wove gracefully across the room despite looking entirely out of place and stood staring down at him. Shin picked his way along in her wake, awkwardly standing behind her shoulder.

“What?” Go lowered the weights and unhooked his ankles from behind the bar. “I don’t skip leg day.”

“You – that’s not important.” Kiriko shook her head.

“Leg day is _so_ important.” Go stared at her, deadpan, rewarded for his needling when Kiriko frowned harder.

“Come with me,” Shin interrupted. “I want your help with something.”

“Of course you do,” Go muttered, and got the explanation on the way out the door; a rash of serial bombings, except that no one could find traces of a bomb at the scene. Each incident was called in and the buildings evacuated, the explosions coming precisely at the time stated in the warning calls. In each case, the buildings had been successfully cleared of civilians, but three officers had been injured so far.

“And the next site?” Go prompted, because he wasn’t going to climb back into the Tridoron if he could help it. It had been enough trouble getting his bike back from the Drive Pit the last time.

“Kuruma Leisure Amusement Park,” Shin said, and Go knew exactly where it was. “The deadline is 3pm.”

“Evacuation?” Go asked, and nearly missed the answer in the time it took to jam his helmet over his ears.

“Under way,” Kiriko repeated.

Go reached the amusement park before Shin could, the Ride Macher splitting lanes and cutting through traffic, and found it swarming with officers in vests. He triggered the transformation before he skidded to a halt and leapt the fence, but the bomb was nowhere to be seen. The officers started streaming out almost as soon as Go got inside, and it was almost time for the bomb to explode, and Go couldn’t _find_ it.

“Is it microscopic?” he hissed across the comm. “Or invisible?”

Shin ignored him entirely, and Go swung up onto the ferris wheel. There was no way to search the entire park in just a few minutes, particularly not if the bomb was hidden, or disguised to look like something else.

“It’s time,” Go heard Mr. Belt say to Shin, and a sudden wave of hot pressure sent him flying straight at the ground. It was sheer luck that let him hit the ground and roll to bleed off the momentum, the armor staying in place. He blinked at the sky, dazed, until Shin’s helmet suddenly filled his field of vision and Shin was asking him a question he couldn’t quite make out.

“I’m doing _great_ ,” he said. He couldn’t feel his fingers, but he could hear footsteps approaching and from the way Shin stood up and spun around, they weren’t friendly.

“Roidmude!” Shin said, standing defensively in front of him.

Blood pounding in his ears, Go tried to stand. It did not go well. He tried again, as Shin ran toward the Roidmude, only to be hit by something Go couldn’t see. He kept trying until he made it up on his knees long enough to stuff Signal Tomarle into the Mach Driver and freeze the Roidmude into place. To Go’s annoyance, the Roidmude bounced right back, but instead of coming for them, it gave a mocking half salute and ran off.

“Son of a _bitch_ ,” Go said, and tumbled right back over.

Much to Go’s chagrin, he couldn’t stand without help, nor could he get himself onto his bike. He refused to leave it behind, pitching enough of a fit that Shin – both in considerably better shape and inexplicably possessed of a motorcycle license when all Go had ever seen him drive was cars – drove the Ride Macher back to the Drive Pit and Kiriko piloted Tridoron with Go in the passenger seat again. He considered it a minor victory that he didn’t end up in a hospital to be examined, until they reached the Drive Pit and Kiriko wanted to know where Mad Doctor was.

“I haven’t seen him,” Krim said, and swung his mobile stand over to face Go. “Kiriko?”

“Huh,” Kiriko said, and Go missed the rest of her reply as he limped over to where Shinnosuke had parked the Ride Macher.

“Who said you could leave?” Kiriko asked acidly, and Go learned that his sister knew enough first aid to at least patch up the visible damage.

“It doesn’t hurt,” he said, although his side was killing him. “Nothing broken on the inside.” Probably, he added mentally.

“Still,” Kiriko said worriedly. “Rinna, have you –“

“Not now,” Rinna said, too busy working on a support system for Drive to safely use Type Formula to do more than give them a very short explanation of what she was up to, and Go smiled bitterly.

 _Another upgrade for Drive, then_ , he didn’t say out loud. Drive had defeated Chaser, Drive had been the one to actually face the Roidmude today while Go had been useless; he couldn’t even take care of an already defeated opponent.

“Go.” Kiriko was snapping her fingers in front of his face, and Go blinked. “You really –“ she started, and he shook his head.

“I’m good. Let me know next time you need something.” He couldn’t stop the sarcasm from leaking into his words, but Kiriko let him go this time. His muscles had loosened enough to let him climb onto the Ride Macher without much difficulty and drive it back through the gathering twilight gloom.

The lights in his apartment were off when Go pushed the door open and left his shoes in a heap next to the step up out of the entryway, and he thought the Roidmude had maybe gone. Instead, he found it sitting crosslegged on the living room floor in the dark, kotatsu quilt neatly folded.

“I don’t have time for this,” he said, turned around, and closed the kitchen door behind him. He crawled onto the bed with a sense of relief, vaguely aware that his jacket needed to be washed and there was still stone dust ground into the palms of his hands but too exhausted to care.

The Roidmude hadn’t stirred from the room when Go stumbled into the kitchen to make coffee on waking; it was still sitting next to the door, and between the muddled dreams that wouldn’t let go and the soreness from the day before, he’d entirely forgotten it was there. Seeing a figure seated in the doorway startled him badly, and his already stiff muscles seized when he flinched; Go tripped over nothing and had a split second to be annoyed that he was going to end up on the floor for no good reason before he landed on something soft instead.

It took several seconds for Go’s brain to catch up with the rest of him, finally sorting out the contradictory sensory information to tell him that the Roidmude had caught him. It was crouched with one knee touching the ground, Go pressed up against its studded jacket with his legs folded awkwardly underneath him. He could feel a steady pulse, where it held him tightly, and he wasn’t sure if it was his own heart or if the Roidmude had copied that too.

“Are you all right?” The Roidmude’s voice was low, lips nearly touching Go’s ear and sending a shiver through him. He pushed it away, scrambling backwards and knocking his sock-clad heel against the doorframe. The Roidmude didn’t so much as overbalance, hands hanging uselessly over its thighs as it looked at him quizzically.

“I thought I told you to stay in that room.” Go said the first thing that came to mind, on his hands and knees on the kitchen floor with zero sense of equilibrium. He stood, slowly, deliberately not looking at the way the Roidmude seemed – again – to be disappointed.

“I owe you a debt,” the Roidmude said, and it had tried this tack before. “Isn’t that a human rule?”

“What? No. Maybe. Not here.” Go started toward the coffeemaker, trying to regain some semblance of control. If he wasn’t distracted from what he’d initially come into the kitchen to do, he hadn’t let everything go. “I told you, you don’t owe me anything.”

If the Roidmude had been human, Go would have said it was frustrated. It stood smoothly, jacket falling into place without prompting, and Go suppressed a flash of irritation. His t-shirt was still bunched up around one shoulder and across his hips, and he pulled it straight with jerky movements. The unthinking motion made him hiss in pain as something caught across his ribs where the explosion had tossed him off the Ferris wheel the day before, and the Roidmude started forward again.

“I told you to –“ Go cut himself off and poured water into the tank. Filter and a measure of coffee, and he viciously stabbed the start button. The Roidmude was standing in the door, watching him, and now he couldn’t help but see it as unhappy. “What,” he said, finally, when its unwavering gaze became too heavy to ignore.

The Roidmude opened its mouth as if to speak, but before it said so much as a syllable, it sank slowly toward the ground. Its knees folded in slow motion, and it nearly overbalanced before Go reached out without thinking and steadied its descent. It looked up at him, eyes heavy-lidded. “Thank you,” it said quietly, and Go pulled his hands away as if they’d been burned.

Mad Doctor was still on the table behind him; Go snatched it up and couldn’t remember for a moment where he’d left the Break Gunner. The Roidmude watched him leave, unnatural purple eyes glittering between its dark lashes, and had its gaze fixed on the door when he came back. Go locked Mad Doctor into the Break Gunner and activated the Shift Car again, gritting his teeth against the sight of the Roidmude arching painfully back under the cascade of electric energy. He helped it back into the living room, after, spreading the quilt over it and freezing with his hands still gripping the edge of the blanket when he realized what he was doing.

“I hate you,” he said to it, but its eyes were shut and its mockery of human breathing was even, and he couldn’t tell if it heard him or not. Go turned off the coffee maker and fled.

The second time Shin walked into the door at Go’s gym was almost déjà vu; Go looked up at the sound of the door to see Shin stalking down the aisle, and barely had enough time to set the weights down before Shin was staring at him with a mixture of concern and apprehension. “There’s another one,” Shin said, and Go had worked out enough of the stiffness that he was able to grab his belongings without a hitch.

Shin gave Go the details through the Mach system’s radio, on the way over to the site, after Go flatly refused – again – to leave his bike behind. Go didn’t listen particularly carefully, when all he needed to know was that Shin had found the Roidmude would point him at it. They arrived on site, Shin still not wearing the armor, and Go followed him to where the Roidmude was making grandiose claims to no audience at all. Go hung back, letting Shin explain exactly what he’d figured out about the Roidmude – it wasn’t setting bombs, it was firing tiny super-fast missiles – and this time Go wasn’t going to let it get the better of him.

The Roidmude started by firing its missiles at all four of its stated targets, and Shin raced off to catch them before Go could do so much as blink. He switched over to Type Dead Heat, knowing he had a time limit, but it would give him the speed he needed to block the Roidmude’s shots before they hit him. For one glorious moment, the Roidmude couldn’t touch him and it felt amazing; Go had it on its knees until the suit started to overload and then it drove him into the ground. Go couldn’t dodge, and the Roidmude got off a shot lucky enough to damage the Mach Driver.

Shin rescued him, because Go couldn’t catch a break and all he did was make things more difficult for Drive. He hadn’t been able to stop the Roidmude the first time, and this time he still needed Shin to rescue him. He left, as soon as Shin’s victory was assured.

“All I do is run,” he murmured to the inside of his helmet before jamming it on his head, but the Mach Driver was ruined and the only place he could go was back to the Drive Pit to ask someone else to make up for his failures. That Rinna – despite her melodramatic cry of anguish – didn’t so much as flinch when he handed her the Driver only made it worse.

“This isn’t your fault,” she said, when he hovered at her shoulder. “Now go away and let me fix it in peace.”

Go curled up on the bench across the room; if Rinna was going to be stuck in the Drive Pit working on his mistakes, the least he could do was keep her company. He didn’t count on it being quite so boring, after a while, but he made himself sit still and watch from a distance. It was hard to see what Rinna was doing, but some of what Go could read was familiar, and he inched closer without intending to until he was nearly on top of Rinna again.

“Go,” she said, exasperated, and he blinked. “You really don’t have to stay.”

“I just want to help,” he said. “I need to be stronger. To defeat the Roidmudes.” He caught himself just before adding the phrase _before it’s too late_ ; she didn’t need to know about his father, either. No one did, not until Go had undone what his father had wrought.

“Go,” Rinna said again, setting down the damaged part of the Driver she was trying to rework. “I can put the Driver back together, but I don’t have an upgrade for it.”

Go bit his tongue and went back to the bench; he’d take what he could get, even if all of the upgrades went to Shin. The less advanced system. He sat cross-legged, staring at Rinna from as far away as the room permitted, eventually waking to see most of the lights off and Rinna shaking his shoulder.

“Go home,” she told him. “I’ll let you know when the Driver is finished.”

As if he could just _leave_ ; Go curled up in the Special Investigation Unit’s office instead, close enough to the Drive Pit that he didn’t feel as though he were leaving entirely, but far enough away that Rinna didn’t glare at him through the walls to leave her alone. He shifted restlessly, sleep coming hard.

The sky overhead flickered between blue and pale gray, zeppelins bearing an unfamiliar logo fading into the clouds one moment and gone the next. It stabilized into a white-edged blue, arching over the colorful buildings downtown. Kiriko stood in front of him, glaring at nothing in particular while talking on her cell phone.

“He fell asleep,” she told Go, and Go shrugged and grinned.

“Then it’s just us,” he said, and time slipped away. The darkness of a theater surrounded him, cartoons dancing across the massive screen and a shiver of remembered pain ghosting across his skin. Go stilled, hand in a popcorn bucket and covered with salt, and he pulled it out.

“What’s wrong?” Kiriko whispered, and Go shook his head. She stood up and walked out of the theater, walking straight down the aisle as if the laughing audience didn’t exist, and Go followed her. He had to climb over crossed legs and poorly placed bags, scrambling to catch up with his sister, trying to apologize to the people who refused to move aside. None of them reacted.

The streets were empty, when Go finally got outside, Kiriko nowhere to be seen. “Kiriko!”

No answer, but the sounds of a fight from the next street over caught his attention and Go took off at a run. A Roidmude – at least, he thought it was a Roidmude – was facing off against an unfamiliar figure. It might have been a Kamen Rider, in another life, green and black armor accented with a brilliant gold, and it tugged at something inside Go’s memory. He thought he saw another figure, shadowy, but no matter how he stared, it wouldn’t come clear.

The Roidmude threw the maybe-Rider into a wall, and Go dashed forward. “Tracking! Terminating! Both done at mach speed!” He shouted his own name, barreling into the Roidmude with both feet extended. The other maybe-Rider climbed to his feet, and swung a dramatically-bladed sword across the Roidmude’s back. It went down, and Go found himself standing over its smoking corpse.

“Cocky, aren’t you,” said the maybe-Rider in green and black, and its armor fell away. The man underneath had a face that felt like it should have been familiar, dark feathered hair and pretty eyes, and Go grinned at him.

“Just a little,” he said, and something grabbed him around the neck. It yanked him backwards, cutting off his air and dragging his heels across the pavement. Go yanked at it, the edge of his vision sparking, and a surge of energy poured through the binding around his neck. Heat blossomed behind him, a painful wall shoving him forward but the grip around his neck wouldn’t let him move. The impact shoved what little air was in his lungs out of his body, and then it fell away.

Go felt himself hit the ground, air refusing to come, and the burning agony across his chest spread outward. He couldn’t move, couldn’t speak, and then he came awake, gasping for breath. The Special Investigation Unit’s office was around him, the air still and suffocating, and Go stumbled upright to shove open a window. The cold air outside cleared his head, and he could see the light of false dawn just starting to spread over the horizon.

“Fucking nightmares,” he muttered. His clothes were damp with sweat, clammy against his skin, and he had no choice but to go home to change. He deliberately left the kitchen door closed; the living room door beyond it was open, and Go didn’t want to look at the Roidmude he was inexplicably harboring. Remembering on his way out the door that Mad Doctor was still on his kitchen table almost had him turning back for it, but the little thrill in the pit of his stomach at the thought of seeing the Roidmude’s face sent him out the door without looking back. _I don’t want to see him. I don’t even want to look at him._

The traitorous sense of anticipation didn’t abate, only fading into obscure disappointment as he got farther away from his building, and Rinna was somehow still working when he let himself back into the Drive Pit.

“I told you I’d call you,” she said, but he dropped off coffee and breakfast – admittedly, he’d given her convenience store food, but he couldn’t cook if he couldn’t get into his kitchen – and her eyes lit up. “You’re a godsend,” she told him, and the coffee was gone almost before Go could return to his bench.

The second day of waiting passed even more slowly than the first, Go eventually giving in to perform calisthenics in the open space of the Drive pit, until Rinna chased him out and he went running instead. Go slept at home, that night, eating convenience store rice balls and staying out of the kitchen and the living room beyond it. If he didn’t look at the Roidmude, maybe the problem would vanish without his having to solve it.

 _I’ve never run from anything in my life_ , he thought fiercely, staring at the closed door, and knew he was wrong. He still didn’t open it, picking up vending machine tea and bringing Rinna canned coffee. She stared at him blankly before taking the can and going back to her work, and Go tried to make himself unnoticeable on the other side of the Drive Pit again.

“There’s a Density Shift reaction!” Krim’s voice startled Go out of his near-total focus on the last of a new series of calisthenics, and he tripped over his own feet.

“A what?” he said, but he was already tugging his shoes back on.

Rinna held out the Driver. “Good as new,” she said, rolling her shoulders, and held up a hand before he could open his mouth. “I can’t promise anything,” she said, but it lit a fire of hope all the same. Maybe if the Driver could be upgraded, it would make up for some of Go’s shortcomings.

When Go got to the location of Krim’s Density Shift reaction, he was faced with the walking dead. The Roidmude that Shin had allegedly destroyed was not only alive, but it was taunting him with his own failure.

“Like I’m not going to kick your ass this time,” he snarled at it and went straight into the Dead Heat armor. He was ready for its tricks this time, or thought he was, and knocked most of its darts aside. He caught the last three, just to be dramatic, and laughed in the Roidmude’s face.

“I wouldn’t be so cocky if I were you,” the Roidmude told him, and a tingling followed by numbness spread out from the hand holding the darts. They tumbled to the ground from suddenly nerveless fingers, and Go realized he’d been poisoned.

“That’s cheating, you son of a bitch,” he gasped. The numbness gave way to pain, rapidly spreading up his arm and through his chest, and he barely felt himself hit the ground. The Roidmude disappeared, and Go’s armor followed. He thought he heard Kiriko shouting his name, and then something about Mad Doctor going missing, and everything went dark.

* * *

_Core function, protect._

Chase lay still, hands at his sides, toes pointed at the ceiling. The shadows played over the textured paint, sliding down the smooth walls. He couldn’t see where the wall met the floor, at this angle, the clean angles of the room’s construction interrupted only by a boxy hanging light in its center.

The light was off.

Chase cycled through his breathing, a human approximation, a subroutine designed to enhance his ability to blend in with humans when taking human form. It hadn’t been one of Krim’s designs; it had been Banno’s innovation. Krim hadn’t bothered to give him a human face, or even a name, preferring that his creation look like exactly what he was – a Roidmude, and later, a Kamen Rider. Mechanical beings didn’t need to breathe. Mechanical beings didn’t need to be called by anything other than a number.

Chase still held the name _Proto-Zero_ dear, a comforting refrain deep in the recesses of his memory, even if that was no longer how he thought of himself. Heart had forcibly stolen that name, along with Chase’s memories, when he’d reprogrammed Chase’s primary purpose from defense of humanity to defense of the Roidmudes; he hadn’t been able to alter Chase’s most basic drive, simply shift its focus. Protection was built too deeply into Chase’s core.

The breathing, though, that had come along with the reprogramming and Chase’s first taste of looking like the humans he had been taught to hate. It had bothered him, at first; the unconscious rhythm to make his chest rise and fall a waste of both energy and valuable processing power. Trying to suppress it while wearing a human face became uncomfortable, and Chase eventually accepted it as the lesser of two evils.

Sometimes he thought that Krim hadn’t minded if he looked like a doll, hadn’t thought he was truly alive, and that was why Krim hadn’t shown him how to breathe. Breathing meant life, and the Roidmudes knew he was – gloriously – alive. When had he ceased viewing it as a necessary evil and started to feel that it represented proof that he was his own entity? Chase had no idea. It wasn’t helping him now.

Tomari Shinnosuke had tried to kill Chase, as was right and proper and expected, after Chase had done his level best to destroy Kamen Rider Drive, and Kamen Rider Mach, and support the Roidmudes in their grand plan. He didn’t know what that plan was, in its entirety, but he didn’t need to know. He only needed to go where he was told and do what he was ordered to do, and demonstrate that he was loyal, except that he hadn’t always been loyal to the Roidmudes.

 _Proto-Zero_ echoed across his mind, and _Proto-Drive_. He’d been both. He was Mashin Chaser and he was Proto-Zero and the two were inimical to each other, and he could not fulfill both roles at once. It had to be one or the other, and Tomari Shinnosuke had tried to kill him.

Shijima Go, despite his consistent and very vocal hatred of Roidmudes, had tried to save him.

 _You’re one of_ them _, you wouldn’t understand_ , he’d said. Chase fought the urge to writhe, to move as though it would dispel the conflicting impulses generated by two sets of programming. The deeper network, which couldn’t be erased, and the overlay that had provided him with true life, and they were at odds. But Shijima Go had rescued him, and kept him safe.

Chase moderated his breathing yet again, forcing himself to lie still and straight. Most of the repairs were finished, only a few touches to the power relays between his Core Driviar and his mechanical systems. In a few hours, he would be able to slip out the door and return to his role as – as what? Chase’s fingers twitched at the restoration of another connection, the lightness returning to his left hand, and he held it motionless. _A few hours. No more._

There was a decision to be made, and Chase had no idea how to make it.

* * *

“I wanna go home.”

Kiriko ground her teeth, trying not to show her frustration. Her recalcitrant sibling had only gotten more stubborn in the time he’d spent abroad, without structure or routine or anything resembling adult supervision. She wasn’t convinced Professor Harley counted, not when Go had – by his own admission – spent months on the road doing, as far as she could tell, nothing at all. She’d wondered, occasionally, how he’d managed to maintain a visa, with that type of behavior; that Go had shown up again, out of nowhere, with the Mach Driver and a cocky attitude had been both amazing and aggravating in equal measure.

“Kiriko,” Go said, staring up at her. “Mad Doctor can stay.”

“You shouldn’t be at home,” she told him. Mad Doctor nearly hadn’t made it on time, and there had been a terrifying moment in which she’d been sure Go had stopped breathing. She didn’t think he should stay anywhere alone, and the Shift Car didn’t count as company. As if it knew what she was thinking, the tiny machine vibrated unpleasantly in her palm.

“Don’t make me,” Go said, and clenched his jaw shut. His face went from pale to almost greenish for a moment, until he relaxed minutely and a little of his color came back. “Please,” he said, and Kiriko had never really been able to say no to her little brother.

“Don’t throw up in my van,” she said, and was rewarded with an attempt at a smile. “This is going to go so, so badly.”

The interior of the van remained more or less clean; the problem Kiriko ran into was hauling her now mostly-asleep brother up three flights of stairs, and searching his pockets for his keys. She glared at the peeling green paint on the door when she finally found them, offset by a hole in the center of the mailbox slot cover, and thought yet again that she shouldn’t be letting Go try to make it on his own. Not until he grew up a little more, developed more of a sense of responsibility, instead of renting apartments with holes in the doors and nearly getting himself killed by Roidmudes.

Kiriko nearly tripped on a pair of boots left in a heap off to the side of the entrance, heavy and black and unlike Go’s usual colored sneakers. He was wearing the sneakers now, but she got him awake enough to take them off before pushing him into the first door on the left. It was the bedroom, with a futon set spread across a low bedframe under the window, and Go dropped heavily onto it. Kiriko wasn’t convinced it wouldn’t break, but it only creaked under Go’s weight.

“I’m okay now,” Go said, and to his credit, he looked more alert than he had since 091 had returned from the dead and poisoned him. “You can go.”

“Don’t be ridiculous,” Kiriko snapped, and then regretted her tone. “I want to make sure you’re all right,” she said, more softly.

“I’m fine.” Go drew his knees up to his chest, the way he had as a small child right after their mother had been slaughtered by an unidentified creature. Kiriko had known the truth. She’d told Go that there had been an accident, and as far as she knew, he’d never learned the truth. Most of the time, he’d overcompensated by being louder, brighter, more energetic; every once in a while, he’d gone nearly silent and tried to make himself smaller. He had that same body language now.

Kiriko sat down next to him, slowly, and tugged him down to rest against her shoulder. She’d done that, too, when he had been smaller than she was and she had still been so very young but the only one that her brother could depend on. It was harder now, to get him to fit under her arm, with the way they’d both grown up. Kiriko managed it, stroking his arm with one hand. “I know,” she said, instead of the myriad things she wanted to say. “I know.”

It didn’t take long for Go to fall asleep, exhausted by the poison and Mad Doctor’s treatment. Kiriko nudged him the rest of the way onto the bed, pulling the futon over him, and pulled Mad Doctor out of the slot on her belt. She set it on the windowsill, just barely wide enough to hold it, and looked at it for a moment.

“Keep an eye on him, after I leave,” she said. Mad Doctor hummed a little, rocking back and forth before settling into the corner.

Kiriko padded back out of the room, sock feet making almost no sound on the tatami mats of the bedroom or the polished faux wood of the hallway. The door at the end of the hall was closed, the only light shining through the hole in the mail box – there was a matching hole in the box fastened to the inside of the door, not just on the slat covering the entrance, Kiriko noticed. Cold air drifted into the hallway, and she frowned at it.

“You’re going to freeze to death,” she muttered; she had no idea why Go hadn’t fixed the hole, or at least patched it with something, but it was something she could take care of while she decided whether or not she wanted to leave her little brother alone.

Neither of the other doors to the sides of the hallway were useful; one led to a washroom with a sink and a shower, and the other was the small and separate toilet stall. Kiriko opened the fourth and final door, opposite the front door, and found a narrow kitchen. The blinds on its other side were firmly closed, blocking out most of the mid-afternoon light, and Kiriko frowned. Go had always liked seeing the sky, and if he was shutting it out, there was something seriously wrong.

“Tape,” she muttered. She couldn’t do anything until Go was awake; going through his belongings in an attempt to fix his door was one thing, but trying to pry into his mental state was more of an intrusion than she was willing to make. She found tape in the closet cleverly hidden behind the kitchen door, noting in passing that yet another door, presumably leading to a living room, was firmly closed as well. “Why don’t you leave doors open?”

Hole in the front door secure, she went to return the tape to the kitchen. She didn’t get past the half-open door; it met resistance as she pushed it. Kiriko shoved harder, and the door creaked open to reveal a human figure standing on the other side. For a moment, Kiriko’s mind refused to parse the sight, throwing random shapes and colors with no context at her. Glittering purple, smooth pale peach, and fluffy black finally resolved into a familiar face, and Kiriko bit the inside of her cheek just to make sure she wasn’t somehow dreaming. She was standing in Go’s kitchen, and the former Proto-Drive was standing in front of her, wearing the human face he’d adopted when he’d been defeated and turned by the Roidmude leaders.

“Chase?” Kiriko couldn’t hear her own voice over the pounding in her ears. She cleared her throat and tried again. “ _Chase_?”

The Roidmude nodded slowly, without saying a word. Kiriko had seen him die, had seen Shin destroy him as he wore the form of Mashin Chaser. She’d mourned his death, in that she’d known he would have been a strong ally and possibly even a friend, grieved the lost potential of the construct that had saved her life on the night of the Global Freeze. Finding him standing in Go’s kitchen, as if it were the most natural thing in the world, was disorienting.

“What are you _doing_ here?” Kiriko found herself clutching the tape, holding it between them like a shield, and she put it down on the kitchen table with a loud thunk. “Does Go know – of course he does.”

Chase nodded again and stepped back. He wasn’t moving quite smoothly; there was a hitch to his right leg and his left elbow was unnaturally straight. Kiriko looked at the hole in the door and thought about Mad Doctor going missing. She came up with the conclusion that Go had borrowed the Shift Car to repair the Roidmude in front of her, and frowned at Chase.

“That doesn’t answer my question,” Kiriko said; her brother’s hatred of the Roidmudes was well established. It was, perhaps, somewhat irrational, but Go had never wavered. She couldn’t think of any reason for him to save any of them. “What are you doing here?”

“Shijima Go rescued me,” Chase said, deep and toneless. He closed his mouth, clearly finished with an explanation that told her absolutely nothing.

“Why?” Kiriko asked. Chase blinked, backlit by the dim blue light through the tightly closed blinds, and it occurred to Kiriko that Go hadn’t been blocking out the sky. He’d been hiding Chase.

“He said.” Chase paused, pulling her attention back to him. “He said I wouldn’t understand. Because I’m not human.”

“ _I_ don’t understand, and I’m his sister,” Kiriko muttered, and felt heat starting to crawl through her veins. She was angry, she was surprised to realize, angry and disappointed that her brother had kept this a secret from her. “Did he tell anyone else about you?” Chase looked at the floor, instead of answering. “You have no idea.”

“I tried to kill all of you,” Chase said, before the anger could really take hold, and derailed Kiriko’s train of thought. “Why don’t you think I am here for that purpose now?”

Kiriko opened her mouth and closed it. It hadn’t once occurred to her that Chase would have stalked her brother, broken into his apartment to lie in wait to murder him. “That’s not the way you are,” she said finally, unable to explain why she trusted that he would at least be straightforward in any further attempts to defeat her brother or her partner.

“Neither of you make sense,” Chase said. “Is this a human rule?”

“This has nothing to do with – “ Kiriko shook her head. “If you’re staying, I’m not leaving.” She pulled out her phone to text Tomari, letting him know that she was looking after her brother.

The reply came quickly; Shin sending her an update on the case. The person responsible had thought it was a game, making a contract with a Roidmude to set off explosions, but the Roidmude had now begun to threaten him. Mogi, that was his name; Tomari referred to him only as _the suspect_.

 _This explains why he’s still afraid for his life_ , Tomari texted her. _If I didn’t destroy the Roidmude, it’s still out there. The Captain’s taking him to HQ._ A pause, and Kiriko had just slipped her phone back into her pocket when it buzzed again. _Bomb threat, at the SIU office, fifteen minutes. Gotta go. If Go’s up to it, send him this way._

“Are you freaking kidding me.” Kiriko looked toward the door, where she could barely see Go huddled under the window. If she woke him, he would insist on going, and it would probably get him killed. Go couldn’t even make it there in fifteen minutes, except – Kiriko thought, her stomach sinking, with her police van, she could probably get him there on time. Go lived surprisingly close to the driving school, closer than Kiriko did.

“Is something wrong?” Chase asked, and it was timed so perfectly that Kiriko told him.

Chase regarded her for a moment, and his left arm twitched before relaxing into an almost natural slight bend. “I will take his place,” he said.

“Absolutely not.” Kiriko glared at him. “You’re not going to – to waltz out there and pretend to be my brother.”

“I owe him a debt,” Chase said, but Kiriko could see him wavering.

“You don’t want to kill Roidmudes,” she said quietly. “Let Tomari handle this.” She glanced at the doorway again, and walked back into the bedroom. “Go.”

“Huh?” He came awake quickly, and Kiriko pushed back her misgivings. He would never forgive her if she hid Tomari’s request, and for all of Go’s dramatic tendencies, Mach was Drive’s backup.

“Tomari wants your help at the driving school, if you can give it.” She watched his expression change from confusion to determination, and Go only wavered slightly in climbing to his feet.

“You trust me to back him up?” he said, hesitating.

“I wouldn’t be bringing you out there if I didn’t,” Kiriko said. “You’ve always been the confident one, Go, even when I was useless as an older sister. I trust you.” The half-open kitchen door at her back seemed to press against her senses, Chase standing motionless behind it. His presence was a silent reminder that Go didn’t trust Kiriko the way she was trying to tell him she trusted him.

“You know I trust you, too, right?” Go searched her face, and she saw him glance quickly over her shoulder. He relaxed a little, and Kiriko wanted badly to follow his gaze to see why. She made herself keep looking him in the face.

“I know,” she said. “Come on. I’m giving you a ride.”

“You left my bike behind.” Go frowned at her, a hint of his usual melodrama in it, and Kiriko rolled her eyes exaggeratedly.

“Because I was going to let you drive yourself while you were unconscious,” she said, and it was the wrong approach. Go’s face fell, and he made his way toward the door. Kiriko opened her mouth to try to apologize, but she didn’t quite know how.

* * *

It was dead, the peculiar Roidmude with its fur and brightly colored shell, and Shin was giving Go a worried look. Go ignored it, bouncing on the balls of his feet. The Roidmude had had a partner, an organic monster with the power to turn invisible, and Go was starting to think that they hadn’t been fighting Roidmudes at all.

“Hey,” he said to Shin. “These are weird, right?”

“They’re not any weirder than usual.” The speaker glared at him, arms crossed over his chest as the armor fell away to show his pretty face. “Your robots are weirder than Shocker’s mutants.”

“Roidmudes,” Go corrected absently, and Yuuto – that’s his name, he thought with a vague sense of something falling into place – rolled his eyes.

“Go,” Shin said, starting toward him with the same look of concern.

“Nothing is wrong,” Go snapped, and felt a bolt of white-hot agony slam through his spine. It lifted him and shook him like a rag doll before flinging him dizzyingly to the ground. He heard rolling thunder in the background, felt a wash of flame over his exposed ankle, and none of it mattered across the pain. Pressure against his face took away his breath, but even when he could see the sky, he couldn’t breathe, and then he was suddenly slumped against a window instead.

“Are you all right?” Kiriko peered across the van while Go took a deep and reassuring breath.

“Fine,” he muttered, trying to rub the sand out of his eyes. A faint whisper of remembered pain slipped across his spine, and he suppressed a shiver.

The van swerved off the expected route before they reached the driving school and the Roidmude’s human target; Shin had apparently texted Kiriko that Captain Honganji had handcuffed himself to the suspect and was holding him at the Special Investigation Unit’s main office. The Roidmude had taken said development as encouragement to spark a Density Shift reaction in the nearby Central Park.

Go fingered his repaired Mach Driver, already belted around his waist. He could feel the drag along his limbs, the urge to lie down and go back to sleep tugging at the back of his eyelids. The suit would help, a little, until he released the transformation again. Go rubbed at his eyes, and Kiriko gave him a worried look she probably thought he couldn’t see.

 _At least she didn’t find Chase._ By some stroke of luck, the kitchen door had stayed closed and the Roidmude hidden behind it was his secret for just a little longer. Without being able to explain to himself exactly why he hadn’t just left Chase where he was, when he’d found him broken and dying, Go couldn’t tell anyone else either. It wasn't a can of worms he felt up to opening.

Shin had engaged the Roidmude when Kiriko’s van screeched to a halt, Go jerked back by his seatbelt bare millimeters from the dashboard. He unbuckled it, scrambling outside and sliding the Signal Bike into the Mach Driver. The armor settled around him, the energy of Shift Dead Heat burning through his veins, and he only had a few minutes before he lost control.

“Come on, you bastard!” Go snarled, batting aside the first strike before he remembered 091 had the nasty trick of poison up its metaphorical sleeve. He dodged the second, ducking around Shin to kick the Roidmude off the rooftop it had chosen. 

“What are you _doing_?” Shin dove after it, wrenching himself to the side just in time to avoid what Go could now see was a spray of poisoned darts. Go followed hard on Shin’s heels, so close to being clear of the Roidmude’s assault. He could feel the tip of the outermost dart ripping through his armor, and the sharp-edged numbness started to spread outwards almost immediately.

“Not this time,” he told the Roidmude, and charged toward it with all of the energy he had. Repeated strikes to the Boost Driver poured the Dead Zone’s power through the armor, Go clinging to the edge of control by his fingernails. The Roidmude staggered under his overclocked assault, but refused to fall.

“Go!” Shin called.

“I’ve got this!” Go returned, but his second of inattention had cost him. The Roidmude swung hard, driving him into the ground. As he fell, Go could see what Shin had been trying to say; his finishing move was barreling toward the Roidmude, and Go was in the path of the explosion.

The blast of heat Go was expecting roared past him instead of washing over him, and he had the confused impression of blue-edged shelter before something hit the pavement next to him with enough force to crack it into pieces. Blue sky pressed into his eyes, from outside the visor, and the silence rang in his ears. The entire world felt like it was a step removed, as if he were floating, and Go pushed himself to his feet, not willing to release the transformation.

The Roidmude was gone, its core fluttering upwards. As Go watched, the shining numbers disintegrated into ash. “At least it’s dead,” he muttered, and it occurred to him to look down.

Shin was face down on the pavement, unconscious and bleeding from the ear. Static roared in Go’s ears and he dropped to his knees, reaching for Shin. Kiriko appeared suddenly on his other side, unsteady fingers resting on Shin’s neck. “He’s alive,” she said, and Go went weak with relief.

The transformation slipped away, its aftereffects crashing into Go like a load of bricks. He struggled to pull himself together, but Kiriko looked as though she were on the other side of a thick, wavery pane of glass, and her voice was distant. He could barely feel her hand on his shoulder, shaking him sharply, and the next few minutes were thoroughly disorienting. 

The fog over Go’s thoughts cleared slowly, showing him an unfamiliar room. He sat up, a blanket falling off his shoulders, and recognized it as the Drive Pit with the lights off. A Shift Car he didn’t immediately recognize chirped at him, and Go shivered in the sudden cold. The lights brightened, and he could see that the Shift Car staring at him was Colorful Commercial.

“I’m okay,” he told it. It chirped at him again and raced off, leaving the Drive Pit lonely in its absence.

Go climbed to his feet, stretching. No one else was in the Drive Pit, but his Mach Driver had been carefully placed at Rinna’s workstation, and his shoes were neatly lined up right where he needed them. He put them on, wincing at the pressure against his skin. He felt scraped raw all over, but the leaden weight of fatigue was gone. He blinked for a moment and then went over toward his Driver. His limbs were stiff at first, loosening the more he moved, and by the time he picked up the Driver, he felt almost human.

As if the motion had shaken his brain loose, the memory of the fight against 091 rushed back, and Go took in a sharp breath. “Shin,” he murmured, and searched his pockets for his phone. It wasn’t there, nor was it on the bench. He finally found it at the workstation, next to where the Driver had lain, and snatched it up with shaking fingers.

Shin had gotten hurt, covering Go from the consequences of his own mistakes, and anything that had gone wrong with him would be Go’s fault. Go bit his lip and turned on the screen. He had several messages, but no missed calls, and all of the messages were from his sister. It took him a few seconds to work up enough courage to open any of them; he knew it was selfish, but he didn’t want to read that Shin was dead.

 _Tomari will be fine_ , read the first one, and Go slid down the wall to sit crosslegged on the floor. The rest of the messages were much less intimidating, but each one struck him just a little harder. Shin had sustained serious injuries, and Kiriko felt that he shouldn’t equip the Drive suit for the immediate future.

“I bet Shin feels differently about that,” Go muttered, but Kiriko hadn’t told him exactly how Shin had been hurt, only that recovery would take at least a few weeks. What she didn’t say hung over him, just as painful as the news that he was responsible for his rival and friend’s injuries; not once did Kiriko even imply that, as Mach, he would need to pick up the slack. “Yeah, well, I wouldn’t trust me, either.”

His eyes were burning. Go squeezed them shut and then open again. He sent a text to Kiriko thanking her for keeping him in the loop, and finally noticed the date. It was late Wednesday, and he’d lost almost an entire day.

“No wonder I was so stiff.” Concentrating on the mundane helped push away the knowledge that he’d disappointed his sister; he’d make it up to her, somehow. Go looked around the Drive Pit, searching for his bike. It was nowhere to be seen, and Go remembered vaguely that the last time he’d seen it, it had been at the site of his defeat at the hands of 091. “One of them, anyway.”

Collecting the bike meant it was dark by the time Go pulled up outside the hospital where Shin was currently under observation, unless he’d been discharged while Go was trying to show up and be supportive. No messages to that effect were on his phone; Go stuffed it back in his pocket and headed inside.

Shin was asleep when he got there, door half-open to the hall and lights lowered. Kiriko was nowhere to be seen, nor were any of the other members of the Special Investigation Unit. Go hovered in the doorway for a few moments, indecisive, and finally slipped into the room to scribble a get-well note on a piece of scrap paper. _Tomorrow_ , he told himself. He would bring Shin a proper get-well gift the next day.

The drive home seemed longer, and Go parked the bike under his building in its usual spot with a sense of unreality. It seemed as if it had been an eternity since he’d been home, but he hesitated on the stairs. Chase was, theoretically, still in his living room – and when had he started thinking of the Roidmude as _Chase_ – and Go didn’t think he had the resources to deal with the conflicting feelings Chase engendered.

Go made himself go upstairs, opening the apartment door hesitantly. The mailbox had a hole in it, just the right size for Mad Doctor to have broken through the door, and Go was momentarily distracted enough to curse at having something else to fix. The hallway was dark, but he didn’t need the light to make his way toward the kitchen.

Go opened the door slowly, turning the light on before the door was fully open, but Chase was nowhere to be seen. He wasn’t in the living room, either, although the kotatsu quilt was neatly folded. There was a handwritten note saying simply _Thank you_ in blocky, childish script. Go frowned at it, and then crumpled it in his fist in a sudden surge of annoyance.

“How is it that you drive me crazy even when you’re not here,” he said to the note, and then felt guilty enough to smooth it out. “Goddammit,” he said, with feeling. “Goddammit,” he said again, and suddenly he desperately wanted a shower, as if it would wash away all of the terrible things that had happened over the past four days. He stood out on the balcony, afterwards, shivering in the unseasonable cold and unable to see the stars for the fitful glow of the streetlights.

Out of nowhere, the Roidmude came for him with its incongruous fur lining a spiral shell, and flung a wet gelatinous mass directly in his path. It was a net spread too wide for him to avoid, even with his speed maxed out, and the mental image of a spray of poison darts flashed in front of his eyes. Go tried to duck, but he was caught in a glop of incongruously delicate pink. It froze his joints, where it touched, hardening to the consistency of stone.

“Just keep running,” he told the Roidmude, struggling against its trap. He’d break free. Eventually.

A high-pitched cackle was the Roidmude’s response, and Go heard the peculiar whine that meant it was building up an energy wave. He struggled harder, knowing it was about to kill him if he didn’t move. His feet were stuck fast.

The Roidmude’s strike bore down, crackling as it warped the pavement, and Go saw Shin out of the corner of his eye. The armor flashed around him, dramatic red with its touches of white and black, and Shin was going to be too late. _Wasn’t he injured_? Go had time to think, and then the wave hit him. The trap holding him still splintered as the energy flung him into the ground, the pain of impact shaking him mercilessly, and he barely felt the armor fall away.

“Go!”

It was Shin’s voice, followed by Kiriko, and someone else was shouting his name. Someone he knew, but couldn’t remember, but it didn’t matter. The sky had gotten dark, while he wasn’t paying attention, and he could barely see Shin leaning over him. He groaned, feeling something thick slide out of the corner of his mouth, and opened his eyes to the familiar outlines of his bedroom and a noise from outside that he couldn’t identify.

“This is ridiculous,” he said to the ceiling. It was the same dream, with little variations, always ending in Shin staring down at him in horror in his dreams instead of unconscious on the ground the way he had been in reality. It didn’t take any great leap of intuition to know why the nightmares plagued him every time he tried to sleep, leaving him more exhausted than he had been, and the guilt just kept weighing heavier with every repetition. Go pushed himself upright, untangling his feet from the blankets and rubbing at his face.

In the week since Shin had been injured, no Roidmude activity had been recorded. No Density Shift, no bizarre occurrences, nothing. Chase had been nowhere to be seen, either, and Go refused to dwell on how the absence of his mortal enemy felt like ants under his skin. He pulled on the first set of clothes that seemed more or less clean and ran a hand through his hair. He wasn’t sure if he’d brushed it, the day before, and it caught against his fingers. Go pulled his hand free; it didn’t really matter.

The peculiar buzzing sound he’d heard was his phone, set on vibrate and sitting on the kitchen table. Go picked it up and flipped it open, intending to dismiss the call. His finger slipped and it connected instead. He stared at it, without speaking, and his sister’s voice came across the line.

“There you are,” she said, and Go raised the phone to his ear.

“Hi.”

“Tomari misses you,” she said, after an awkward pause.

“I’ve, um. Been busy.” It wasn’t entirely untrue; Go had been practicing, and patrolling. The Roidmudes weren’t going anywhere, but he couldn’t take them out if he couldn’t find them, and apparently their new game was to hide. Frustrated at the Roidmude decision to hide when they should have been at their most active – they’d temporarily incapacitated Drive, and should have been taking advantage of it – Go hit the streets and searched. He told himself he wasn’t looking for Chase while trying to assuage his sense of responsibility for Shin’s injuries, but the lie ate into him a little more every time he repeated it.

“Busy,” Kiriko said, and the skepticism in her voice all but oozed out of the speakers. “Go, listen, I need to tell you something.”

“I’ll talk to you later,” Go said, and hung up before she could answer. The phone lit up again with another incoming call, and he muted it before stuffing it into his pocket.

 _I shouldn’t have brought him back_. It was regret on top of everything else, eating at him like acid edged with hope. At least no one else knew about his moment of weakness, that he’d seen a human face and let it blind him to what Chase – what the Roidmude was. It was an enemy, and – knowing he should have let it die or put it out of its misery – he’d helped it. He’d healed it, let it go free to continue its malicious agenda.

Even if it had saved Kiriko, the night of the Global Freeze, even if it had been programmed to have a sense of justice or to protect humanity, what it had been created to be had been rewritten. It was evil, and it had to be destroyed, and – Go stopped, one shoe firmly tied and the other only half on his foot. He didn’t want Chase to have to die.

The human face – the face that it had stolen, Go reminded himself – that had looked up at him in Chase’s moment of vulnerability wouldn’t leave his thoughts, lurking behind the nightmares. It was Chase who had fought alongside the unfamiliar Rider, Chase who had stared at him unflinchingly each time he died in his dreams. Go sat on the step in front of his door, letting his heel slide the rest of the way into his sneaker with a thunk.

“I don’t,” he said. “I don’t want it.”

It was wrong – it was more than wrong, it was shameful. The Roidmudes had been created through the hubris and cruelty of his father, and they had taken that cruelty and spread it across the world. They would stop at nothing, to wreak vengeance on humanity – for the ill deeds inflicted on them, without just cause. Go buried his face in his hands.

“I don’t know what else to do,” he said, voice muffled. He had to protect his sister, couldn’t let her find out that it had been their father who was responsible for all of the pain and suffering the Roidmudes had caused. Whether the Roidmudes had a legitimate grievance – that wasn’t the point, couldn’t be the point, not after what they had done.

And yet.

Go didn’t want Chase to have to die.

**Notes for the Chapter:**

> The first draft got away from me and is still incomplete, but I said January and I meant it. If the conclusion necessitates editing anything that's been posted, I will let you know, haha. Updates to come on Sundays, until I run out of what I've written or post the final chapter, whatever comes first.
> 
> PS - not all of the chapters are this. Um. Long.


	3. Sensitive Dependence

“The trash heap strikes again.”

Kiriko ground her teeth, closing her phone with more force than necessary. Over a week, and she hadn’t been able to tell Go that she’d seen Chase in his apartment. He hadn’t told her, hadn’t trusted her. She kept trying to draw him out, and he kept pulling farther away. She glared at the phone for good measure, its dead air mocking her with the knowledge that her brother had hung up on her.

“Are you even listening?”

Summoning reserves of patience Kiriko knew she had and desperately did not want to use, she put on her best bland smile and turned to face the new head of the First Investigative Division. The previous head had been quietly retired, or so ran the rumor mill; Captain Honganji had been released to return to his properly assigned duties instead of babysitting the First’s former manager. In Kiriko’s opinion, the change was not an improvement. From his annoyed expression, although one had to know Captain Honganji rather well to see it, he felt the same way.

The new commander – and Kiriko had to dredge his name out of where it was trying to escape into the depths of her memory – missed the edge to her smile entirely, and beamed at her condescendingly. “That’s better, little lady.”

“Officer Shijima, at your service,” Kiriko said, as formally and politely as she could.

“Why was it I came down here? Oh, yes.” Nira smirked briefly, the expression sliding off his face like oil. “Stop attempting to corrupt my officer, Honganji.”

“Sir.” Lt. Otta opened his mouth and closed it again, unable to protest without exhibiting insubordination.

“In fact,” Nira continued, stalking around the edges of the room, “I’m not sure this department continues to justify its existence.”

“You’re so wrong about that.” The voice came from the back corner, where Saijo Kyu was staring fixedly at his computer screen, and Nira pounced on it.

“You!” he crowed, almost gleefully. “You’re not even a member of the police department! Honganji, you can’t just take civilians off the street, like lost dogs.”

“I’m not a –“ Kyu started, and Kiriko covered his mouth firmly before he could make the situation worse.

“Mr. Saijo,” Honganji said, not quite emphasizing the honorific, “is an invaluable asset to the Special Investigation Unit.”

“Investigation.” Nira snorted. “I don’t see that you’ve gotten much investigating done. You may need to be shut down, if this state of affairs continues.” He glanced around. “And your full complement isn’t even here. Honganji, really, now, I thought you’d at least manage to motivate your personnel to show up.”

“If you’re referring to Officer Tomari,” Honganji said stiffly, “he was injured in the line of duty and currently in recovery.”

“I read the report,” Nira said dismissively. “Shocking incompetence. Could have been avoided.”

Kiriko saw red. She couldn’t wrap her hands around Nira’s bony neck, for his disparagement of Tomari’s contributions; for some reason, she couldn’t move her arms, or step forward, and there was pressure against her lips. Nira was looking at her, calmly, one eyebrow mockingly raised, and Kiriko returned to herself in a rush. Kyu and Rinna let go of her, slowly, and Kiriko straightened her uniform.

“Regardless,” she said, proud that her voice only shook a little. “Officer Tomari was doing his duty, and should not be penalized for his absence.”

“Well.” Nira looked faintly disappointed, Kiriko thought, but the expression was gone so quickly she wondered if she had imagined it. “Washed up here after what happened to his father. I don’t know what else I would have expected, really.”

Kiriko held herself still and straight, not opening her mouth. She didn’t trust herself to speak, not when an unqualified and over-promoted buffoon was making unsubstantiated claims about the person Kiriko respected more than anyone else in the Special Investigation Unit or out of it. “Sir,” she said finally, the single word like ground glass in her throat.

“Lt. Otta.” Nira spun on his heel, after staring at her searchingly for an interminably long moment. “Come.”

“Yes, sir.” Otta threw a glance across the room, shrugging apologetically behind Nira’s back and straightening into proper posture when Nira threw a glance over his shoulder.

“That – that rat bastard,” Kiriko said, when the door closed.

“Don’t let him get to you,” Honganji told her. “He’s just trying to get a reaction.”

It would have been good advice, if it had come from anyone other than Kiriko’s current superior officer, cradling a waving lucky cat in one hand and wiggling its paw at her. Kiriko frowned and stalked out of the room. Tomari’s absence had been lucky, she thought; he’d shown up in the office three days after the fight, not an hour after being discharged from the hospital, and she was fairly sure that if a Roidmude had shown up, he would have put on the suit. He wasn’t quite twigging to his own compromised judgment, and Kiriko was fairly sure his probable reaction to Nira’s needling would have gotten him fired.

“First Tomari, then Go,” she muttered under her breath. “Both of them more trouble than they’re worth. And that’s not even mentioning Chase.”   
  


Kiriko stopped in the hallway, phone clutched in her hand again. All of her current problems were caused by other people, and two of them she couldn’t shout into submission. She glanced at the phone, thought better of it, and started walking again. If Go wouldn’t listen to her over the phone, she was going to have to glare at him in person. Before that, though, Tomari needed checking on. Kiriko settled the Drive Driver more firmly in her bag and headed for the parking lot.

Somewhere between the parking lot and the street, Kiriko changed directions. She drove toward the river, with its theoretical peace and its tree-lined banks, an oasis of potential calm. The driving school was far enough away from the center of the city that little pockets of nature weren’t uncommon nearby, but Kiriko wanted to hear the sound of the rushing water.

Tomari’s favorite park was between the river and the driving school, wide expanse of not-yet-green spreading across the ground, and Kiriko steered toward it on a second whim. “Wishy-washy,” she muttered, but there was always the possibility that Tomari was here, instead of where he was supposed to be. Kiriko parked the van and climbed out.

The Driver sat heavy against her hip, and Kiriko rested her hand against its muffled contours. She’d wanted, badly, to be able to use it. She had trained, and practiced, and it hadn’t been enough. Krim hadn’t been able to explain the failure, but Kiriko privately sometimes thought that it was her desire to use the Driver that prevented her from doing so. The system was so closely tied into state of mind that whether or not it functioned effectively – or at all – could vary from one moment to the next.

Kiriko took a deep breath and let it out again. _It would just be temporary_ , she thought, and her grip on the Driver tightened. _Just until Tomari is cleared to return._ It hadn’t been her first thought, on hearing the extent of Tomari’s injuries, nor had it been the second. She had – with Tomari’s permission – seen the images and read the reports, and even with Mad Doctor’s help, the broken bones would need time to knit themselves back together.

“They’re just a little cracked,” Tomari had said, and Kiriko had given him the most unimpressed look she could manage.

“And when you inevitably get hit, again, and they split farther, and the pieces shift, and vital organs get punctured?”

Given that one of the cracked bones was his skull, Tomari was remarkably unconcerned about the potential consequences. Kiriko hadn’t trusted him with the Driver, at that point, but it had been Krim who suggested that he be removed from Tomari’s immediate vicinity for the time being. Tomari had sulked, which Kiriko had felt had only lent strength to her argument. But now, she had the Driver, and she couldn’t depend on luck to keep the Roidmudes quiet until Tomari recovered.

“It won’t work,” Krim said from inside the bag, and Kiriko pulled the Driver out.

“Are you sure?” she asked, but she already knew the answer. “I’m going to walk for a while,” she told Krim. “Please wait here.”

If a belt could look pensive, Krim managed it. Kiriko stored him in the van and drew her jacket closer around herself. The cloudy sky and lack of sun contributed to the early spring chill, and her clothing wasn’t constructed for warmth.

The pedestrian bridges were empty, at that time of day, the park itself still. Kiriko could see a jogger making his – or her – way around the edges, dark gray fading into the buildings surrounding the grassy space, but she was the only person entering the park itself. She meandered across the soft ground, dry after the week of no rain, stopping beneath a tree that should have had more buds. It had been a long, cold winter, and spring was slow in coming.

A second figure had appeared, beyond the jogger, walking slowly as Kiriko was. She looked away as she approached, not wanting to intrude on the privacy of others, but a flash of color drew her eye. She knew that shade of purple, the winking glimmer of reflected light. Kiriko looked up to see a familiar face, and swallowed back the name Proto-Drive. “Chase,” she said instead, but he was too far away to hear. She wasn’t sure he’d seen her, but he froze as soon as she spoke. “Chase!” Kiriko called, and started walking with purpose.

For a moment, Kiriko thought Chase would flee; he hovered, half-turned away, with almost imperceptible movements as if to run. Each time, he pulled back, until she was just outside of arm’s reach, and then he settled slightly.

“You’re here,” Kiriko said. Chase didn’t answer, just continued to stare at her. She couldn’t read his expression as anything but wary. “How –“ Kiriko paused. “I’m glad you’re alive,” she said. “In case I didn’t tell you that before.”

“I don’t understand,” Chase said softly.

“You saved my life.” Kiriko tried to smile, tried to present herself with as much warmth as she could, but it didn’t come easily to her. “I hoped you would be able to protect humans again.”

Chase shook his head. “I know why you wanted me to live,” he said. “I don’t know why your brother helped me.”

Kiriko blinked. “Did – has he said anything else to you?”

Chase shook his head again, more slowly.

“Of course he hasn’t. Stubborn idiot.” Kiriko folded her arms. “Maybe you can tell him to talk to me, the next time you see him.”

“I will tell him.” Chase shifted his weight, looking as though he weren’t trying to run for the first time since Kiriko had approached.

“Can you help us?” Kiriko knew the question was blunt, that it came out of nowhere. “Help humans. The way you were built to do.”

“I’m a Roidmude.” If Chase had been wary before, he was doubly so now. “Humans are – are – “

“We’re not your enemy.” Kiriko impulsively put a hand on his forearm, and Chase jerked away as if he’d been burned.

“Humans hurt us,” Chase said. “They bring nothing but pain.”

“It’s not right to punish all of humanity for the actions of a few.” Kiriko withdrew, letting her hand fall to her side and trying to keep her body language open. “Most of us don’t want to hurt others.” Chase simply looked at her, and Kiriko withdrew. “Tell my brother,” she said. “When you get back.”

Kiriko left without waiting for an answer, turmoil she’d hoped to lay somewhat to rest only stirred up further, and hesitated outside the van. The lack of the Driver against her hip ached with cold, its lightness making itself felt. She shook her head angrily and opened the door. She had work to do and duties to perform.

* * *

“I’m going to take you down,” Go promised, Zenrin Shooter raised.

The Roidmude in front of him threw its head back and laughed, swinging its sword in a wide arc. It cut through stone as if it were air, leaving behind polished gloss, and that wasn’t going to intimidate Go.

“Wait,” Krim said, through the Mach system, and Go growled in frustration.

“Why?”

“Because that’s not just a Roidmude,” Krim answered, and the not-just-a-Roidmude was going to actively murder someone if Go didn’t break the stalemate soon.

“And?” Go demanded. The Special Investigation Unit had called to ask for Mach’s help when a Density Shift reaction had been recorded, and Go had made his way to where a group of prisoners was being transported from one facility to the next. He’d been almost relieved to get the call; at least an aggressive Roidmude was something he could punch without feeling guilty about it.

“He’s fused with a human,” Krim said.

“I don’t see how that makes a difference,” Go muttered, but apparently he wasn’t quiet enough.

“Go,” Krim said sharply.

“I’m going to take him down and we can worry about separating the two of them then,” Go said, and the Roidmude was charging toward him.

Go dodged to the side, swinging the Zenrin Shooter around to catch the Roidmude at the edge of its armor. It staggered back, flesh smoking slightly, and howled in pain. Its voice was a dissonant mix of Roidmude and human, and Go flinched.

“Be careful!” Kiriko said in his ear, and Go bit his tongue.

“You called me to handle it,” he said. “Let me do it!”

The Roidmude took advantage of his distraction to swing its unnaturally sharp blade, and Go swung the Zenrin Shooter up to block it before he remembered how easily it had cut through stone. He altered the angle at the last second, the sword shaving the edge off of Go’s weapon, and skidded underneath it.

“We’re not playing this game,” he snarled at it, and shoved Tomarle into the Mach Driver.

_Signal Change!_ The Driver sang its melody, and the Tomarle’s field flashed out to hold the Roidmude briefly immobile. Go slid Moerl into the Driver, ducking around the Roidmude to hit it with a fireball, and the Roidmude broke through the flames. It hit him with the flat of the sword instead of the sharp edge, opening a long shallow gash along Go’s ribs, and he rolled out of the way.

A second fireball and the Roidmude staggered back. Go didn’t wait for it to recover, rushing forward to leap up and punch downward. The Roidmude started to swing its sword to knock him aside, but it wasn’t fast enough. Go hit it in the face – once, twice, three times – and flipped over its shoulders to land behind it. The Roidmude swung wildly, and Go tried to kick its legs out from underneath it.

The Roidmude slammed its sword into the ground, bare millimeters from severing Go in two, and took off running. Go picked himself up, breathing hard, and started to chase after it. Kiriko’s voice in his ear brought him up short.

“Stop!” she snapped, and years of habit froze him where he stood.

“It’s going to get away!” Signal Kikern was already in his hand and Go flung it toward the retreating Roidmude with a muttered command to follow it. Kikern raced off, little wheels spinning madly, and Go hoped that – for once – the little machine wouldn’t get caught up in a feedback loop.

“I want you at the Drive Pit immediately.” Kiriko’s voice in his ear brought him back to himself, and he hadn’t really thought she would give him the verbal go-ahead to chase the Roidmude.

Go slammed a fist into his palm in frustration and thought for a moment about following it anyway. It couldn’t have gotten far, and Kikern might not be able to follow it. He stalked toward the Ride Macher instead, limbs stiff with anger. “I could have caught it,” he said, quietly enough that he was sure Kiriko wouldn’t hear.

“You would have killed him.” That was Krim, instead of Kiriko, voice colder than Go had ever heard it, and he was wrong.

The second entrance into the Drive Pit – the tunnel, letting out underneath an unassuming overpass not far away – was dark enough to suit Go’s mood, and the roar of the Ride Macher’s engine echoed off the walls. He pulled the bike to an abrupt halt just short of the parked Tridoron and dismissed the armor as he climbed off.

“What were you trying to do?” Kiriko was unimpressed by his theatrics, but she had never taken his image seriously.

“I was trying to stop a Roidmude,” Go shot back. “That’s what we do.”

“Both of you, back off.” Krim’s mobile base rolled smoothly forward, and Go had the urge to knock it over and walk away. He put his hands down at his sides instead, forcing himself to uncurl his fists. “Kiriko,” Krim said, and Go’s sister spun around. She took two precise steps and turned back, arms crossed.

“You’re the ones who asked for my help,” Go said, stabbing a finger toward Krim.

“Taga is a human being,” Kiriko retorted. At Go’s blank look, she frowned even harder. “Taga Hajime. The human that fused with the Roidmude. We can’t just murder a human.”

“How do you know he’s even still alive?” Go said. “Or that the Roidmude can separate them at all?”

“That’s not the point.”

“And we won’t know if it’s just out there, running around, causing trouble!” Go flung his arms wide, looking between Krim and his sister. Rinna was in the background, he suddenly noticed, sitting at her work station and watching the byplay.

“It would help, if we could study it,” she said quietly, when she saw him looking at her. “Or, with a sample, I might be able to modify the Drive system. And the Mach system,” she added hastily.

“Then why don’t I go track it and bring it back.” Go started toward the Ride Macher.

“Sit down.” Kiriko flung out a hand to point at the bench next to the door. “If you can’t follow instructions, you’re not helping this unit.”

“I’m not _part_ of this unit!” Go snapped. “I’m not part of the police!”

“You have the Mach Driver,” Krim interjected. “The Special Investigation Unit and I consider you to be part of our team.”

“The Special Investigation Unit doesn’t know that Shin is Drive,” Go said. “They don’t know that the Drive Pit _exists_. It’s not much of a team if half of it is in the dark.”

“You’re not the one that gets to make that call,” Kiriko snapped back.

“Just because you –“ Go started. He was cut off by the door opening from the outside. A shadow fell across the floor, but no one stepped through. “Now what,” Go said, but Rinna was already at the door, leaning out to look back and forth.

“There’s no one there,” she reported, glancing between Go and Kiriko.

“Right,” Go said, after a pause. “I’m going to go see if I can find this guy. If you figure anything out, give me a call. I won’t kill him.”

Kiriko couldn’t technically stop him, but he could see that she was disappointed as he swung his leg over the Ride Macher and drove back up the corridor. He told himself that he didn’t care; he had a job to do, and he would do it, and even if Taga Hajime was a violent criminal, it didn’t mean that Go was going to misbehave.

Kikern, to Go’s surprise, had stuck within sight of the fused Roidmude. It hadn’t gone on the rampage Go had been afraid it would; instead, as far as he could tell, it was looking for information. He gunned his engine, sliding in and out of traffic, but by the time Go reached where Kikern had last sent the set of coordinates, the Roidmude was gone.

“Are you still following it?” he asked, keying in the appropriate command.

Kikern sent another set of coordinates, farther away than the first, and Go slammed the visor back over his helmet and set off again. And again. And again. Each time, the Roidmude seemed to have fled just before Go arrived on the scene, leaving behind a few bits and pieces of scattered masonry as if to taunt Go with the fact that it could show up and break whatever it wanted, and Go couldn’t stop it.

After the fourth wild goose chase, Go summoned Kikern back; his little Signal Bike was doing its best, but it wasn’t working. He saw why, as soon as Kikern came into view. It had been modified, just slightly, and the Mach system let Go see exactly where Kikern’s external sensors had been corrupted. It had been giving him false data, which meant Go had been sent driving all over the city _on purpose_ , which meant that the Roidmude had a plan.

Go stuffed Kikern into the side pocket of the Ride Macher; it would have to be deprogrammed and debugged, before he could use it again, but he didn’t have time to go back to the Drive Pit. He had one more option, to try to find the Roidmude, and it was one that Kiriko and Shin had both expressed discomfort with. Only hesitating a moment, Go switched on the police band scanner and set the Mach System to search for Roidmude-related chatter.

“Where would I go, if I were a fused Roidmude.” The audio feed went directly into his ear, but he didn’t have a direction. Go started toward the general center of town, going slowly. The humans linked to the Roidmudes had pursued their own agendas, and – if Taga was still alive, as part of the fused monstrosity – Go felt it was fairly safe to assume he would do the same. “But what?”

Not enough information was the problem; Go didn’t have a way to search for it, without stopping, and he hadn’t built up the resources he should have, after becoming part of the SIU team. They’d given him what he’d needed, and Go hadn’t noticed how much he’d come to depend on them until they cut him out.

“There has to be something.”

The scanner answered his question for him, before Go made the decision to stop and see if he could find out something – anything – that might point him in Taga’s direction, with frantic reports of a monster assaulting a hospital. The name was familiar, and as Go drove toward it, he remembered that Shin’s old partner was in that particular building, recovering still from injuries sustained during the Global Freeze. It could have been a coincidence, he thought, or the monster could have been trying to draw out Drive.

“Drive, or Shin,” Go muttered, but the hospital was right in front of him and all that mattered was stopping the Roidmude before it actively killed someone.

The tell-tale high gloss of the Roidmude’s weapon of choice littered the plaza in front of the hospital, and Go could hear screams from inside. He left Ride Macher standing and ran toward the Roidmude, armor clinging tightly to his skin. It hadn’t gotten far, only up to the front desk, and as Go ran through the doors, the Roidmude swung its blade down to smash the reception desk in two. Patients and staff alike fled, and Go grabbed the Roidmude from behind.

It was surprised enough that Go was able to throw it back through the doors, glass shattering in a spray around it as it rolled across the pavement. The Roidmude bounced to its feet with ease, and inexplicably started to run.

“Oh, no, you don’t!” Go sprinted after it. “I’m not letting you go this time!”

Even for a Roidmude, the abomination was fast. Go could hear it panting for breath, but it never slowed. It was always half a step ahead of him, flashing through the alleys and around corners, and as soon as he got a clear view of where it had been, it would be gone again with nothing more than a tantalizing glimpse to lead him onward. The few pedestrians diminished into no one at all, as the alleys got narrower, and then Go burst out from between two buildings into the freezing air of an empty lot.

The sandy ground was churned into deep furrows, dirt spattering the cinderblock wall around the lot, and in the center of the disturbance was a shape that didn’t match the Roidmude. Go walked forward, cautiously, frozen ground crunching under his feet. The shape was whiteish-gray, and he kept feeling that he should be able to recognize the silhouette, but it wouldn’t come clear. As Go got closer, the dark stain under the shape resolved itself from the sticky brown of mud to a dark crimson. With a nauseating lurch, Go realized he was staring at a body.

The corpse’s face was pressed into the dirt, the edges of a gash across its back leaking into the dirt. Something lumpy and indefinable glistened in the gaping center, still moving slightly. Go shook his head, running toward the victim. “Be alive,” he muttered. “Please be alive.” He dropped to his knees, reaching for a pulse, and the victim’s neck gave way under his fingers. It was lying on its back, Go thought faintly, except that its neck had been twisted almost all the way around. The gash wasn’t in its back at all, but in its belly, and Go knew the thick ropy mass of severed guts for what they were. Bile rose in his throat and he clenched his jaw shut.

_I have to tell the SIU that the Roidmude killed someone_. He couldn’t speak; if he opened his mouth, he was going to throw up. Go swallowed hard, squeezing his eyes shut until the nausea subsided, and reached for the Mach Driver to toggle the radio. His gloves were red, and so were his knees. Go scrambled back, tugging at the helmet and vomiting into the dirt on the other side of the body. A shadow fell over him, waiting motionlessly until he finished, and Go scrubbed his mouth with the back of his hand. The scent of blood wafted into his nostrils, and he swallowed again.

The figure standing over him blocked out the sun, backlit, and Go stood slowly. He couldn’t tell who it was until he’d gotten to his feet, and the emotionless mask of Drive’s helmet stared back at him. It was intimidating; Go hadn’t realized quite how menacing it looked, until he was staring at it barefaced and already shaking. In the back of his mind was a sense of relief that Shin had been cleared to return to duty, but it wasn’t important.

“Taga killed someone,” Go said, and his voice was steady enough. “We have to pick him up before it’s too late.”

Drive shook his head. “Shijima Go,” he said, and his voice didn’t sound right. He didn’t quite look right, either, smaller than he should have been, but his next words drove the thought right out of Go’s head. “You’re under arrest.”

“What?” Go stared at him, uncomprehending. The Roidmude had _murdered_ someone, because they hadn’t let him chase it when he’d had the chance, but the SIU had decided to arrest him instead? It made no sense. “You can’t – the Roidmude can’t have gone far, Shin. We have to catch it before it kills someone else!”

“You are under arrest,” Drive said again, the same peculiar timbre to his voice, and Go heard excited footsteps and voices approaching. Drive nodded sharply and picked up Go’s helmet with a swift motion. He jammed it over Go’s head, the helmet clicking into place just as the empty lot started to fill with people. Cameras flashed and Go had the confused impression of uniformed police officers trying to create some sort of perimeter before Drive grabbed him by the arm and dragged him away.

Tridoron was nowhere to be seen; Go found himself perched on the back of the Ride Chaser for reasons he couldn’t understand, Drive’s red suit clashing terribly with the bike’s theme of purple and black. “I have my own bike,” he said, but Drive ignored him, accelerating past the speed limit to make turns with pinpoint precision and screeching into the tunnel leading to the Drive Pit in less time than Go would have thought possible. “Where’s your car?” Go asked, because that was the least uncomfortable question he could possibly ask.

Drive ignored that too, the way he ignored the dark handprints Go could barely see against the red of his suit. Go’s throat swelled again, his gorge rising, and he closed his eyes against the sight of it. The Ride Chaser came to a halt, engine sputtering out, and Go climbed off the back. His gloves were soaked in red, his legs streaked in it, and what he’d thought was dust on his visor was another smear. Go reached for the Mach Driver, releasing the transformation, and had the sudden horrified thought that the blood would fall through the dematerializing armor to land on his clothes and shoes.

His hands were clean, when the armor faded, and Go looked up to see not Shin, but Chase staring back at him from the back of the Ride Chaser.

“You,” Go said, stumbling backwards. “What were you doing in Shin’s suit?”

“Shijima Go,” Chase said, and it was his voice Go had heard through Drive’s speakers.

“I’ll do it,” Kiriko said. Go hadn’t seen her, standing motionless off to the side. She was pale, eyes huge and dark, lips so compressed that they were nearly invisible. “Shijima Go, you’re under arrest for the murder of Taga Hajime.”


	4. Noncentral Trajectory

“You’re fucking kidding me.” Go yanked his hands away from his sister and the curve of hard metal pressing against his skin. “You can’t be serious!”

Kiriko was quicker than Go, and better trained. She let him pull one hand free, keeping the other restrained in half the set of handcuffs with the other in an implacable grip. “Taga is dead, and you were chasing him.”

“That doesn’t mean I killed him!” Go burst out. “He was dead when I got there!” Both Chase and Kiriko were staring at him with identical expressions of skepticism, and Go tried again to get out of his sister’s grip. She didn’t let go.

“The Special Investigation Unit cannot arrest Shijima Go,” came an unexpected voice, and Go felt a flash of warmth for the one person in the room who wasn’t trying to accuse him of a murder he hadn’t committed before he recognized the speaker.

“ _You_ ,” he started to say, but he was drowned out by Kiriko’s exclamation.

“Captain Honganji!” The head of the Special Investigation Unit strolled through the door of the Drive Pit as though he had every right to be there, knew exactly who and what had been using it, and wasn’t surprised at all to find a superhero’s secret base directly below his operation headquarters. He smiled at Kiriko, and she found her voice again. “You knew,” she said, and Honganji rewarded her with a quiet nod.

“Revealing his identity as Mach would only lead the Roidmudes closer to the true identity of Drive,” Honganji said.

“You don’t think they already know?” Kiriko asked, and her grip on Go’s wrist was almost loose enough for him to shake it off.

Honganji shook his head. “I don’t believe they are entirely aware,” he said, and there were shades of meaning Go couldn’t parse and didn’t really want to. He glanced at Rinna, who had stayed out of the confrontation, and she looked almost surprised.

“The police seem to have had very little information on the Roidmudes,” she said slowly. “From the footage of 007 breaking Taga free, they were surprised at both the Roidmude and Mach’s interference. It doesn’t make sense, unless…”

“Unless _what_ ,” Go said, unable to help himself.

“Unless the Roidmudes have infiltrated the police,” Kiriko said softly. “Disseminating false information and making it seem as though the existence of the Roidmudes is nothing more than rumor.”

“It would explain Nira’s skepticism,” Krim said, voice heavy. “But it also means that Shinnosuke is in more danger than we thought. So are the rest of you.”

“Which is why Mr. Shijima cannot be publicly arrested,” Honganji said. “To bring it back to the matter at hand.”

“I didn’t _do_ it,” Go snapped, remembering why they were having this conversation in the first place. “I was chasing it, but I was going to bring it in so they could be separated! I don’t even know where the Roidmude is!”

“Kyu and Lt. Otta found Core fragments at the scene,” Honganji said. “It’s safe to say that the Roidmude was obliterated as well.”

“It wasn’t _me_ ,” Go protested. “I was chasing him, and then I found him.”

“What did you see?” Honganji asked mildly, and Go stared.

“I didn’t see anything! I came around a corner and there he was! Just. Just – like that.” The nausea welled up in Go’s throat again, at the memory of how Taga’s body had been distorted, and he swallowed convulsively.

“I see,” Honganji said, and it was worse than a direct rebuttal would have been.

Go ground his teeth and started to step away from Kiriko, but she tightened her grip at the last second and brought him up short. Go staggered backwards, nearly overbalancing, and Chase reached out to steady him. Go wrenched himself away from the Roidmude, ending up standing behind his sister like a shield. “Don’t touch me,” he gritted out, and Kiriko threw him an exasperated look.

“If we’re not going to arrest him,” she said, and then closed her mouth.

“I think it’s best if he stays here for the time being,” Honganji said. “Yes. Here.” He glanced around the Drive Pit. “The access codes can be activated.”

“What do you mean, access codes?” Go demanded, but Honganji had turned away.

“Captain,” Rinna put in, and Honganji looked up from adding Kiriko to the biometric scanners that Go hadn’t known _existed_ on any of the entrances. As far as he’d known, the door into the Drive Pit hadn’t technically even had a lock. “We have a problem.”

She tapped at her keyboard, bringing a video to full screen. Nira’s arrogant face smirked at the camera, lit by camera flashes and facing a microphone. “Once again,” he said, tugging his already-straight lapels tighter and leaning forward. “The Tokyo Metropolitan Police Department has issued an arrest warrant for the Kamen Rider colloquially known as Mach.”

A picture of Mach flashed on the screen for a moment, dramatic pose outlined against the sky, and shrank back to the corner of the screen to reveal Nira’s smug expression once again.

“Anyone with information related to his identity or his whereabouts will be compensated more than fairly,” Nira said. “He is considered armed and extremely dangerous.”

The text scrolling across the bottom of the screen caught Go’s eye; _Kamen Rider to be arrested for the murder of Taga Hajime, escaped inmate_ was written in spiky colored font, and Go found himself hauled up short.

“Breaking the screen will not help you,” Chase said in an undertone, and Go would have tried to hit him instead if he hadn’t been so off balance. The sense memory of Chase’s soft skin under his hands intruded, uninvited, and Go snatched his free hand away before he could do something ill-advised with it.

“This complicates matters,” Honganji said, and Go’s attention snapped back to the present. “Mr. Shijima, you will stay here. Yes.”

“Those rat bastards,” Go said. “The First Division –“

“This wasn’t unexpected,” Kiriko snapped. “Sit down, Go.”

Go sat, letting Kiriko remove the handcuffs from his wrist. “I shouldn’t be stuck in here,” he said. “I should be out there, looking for whoever did this.”

“Absolutely not,” Kiriko said.

Faced with an impenetrable wall, Go did the only thing he could; he vaulted onto the catwalk around the edges of the room and ignored everyone.

“We’re going to work this out,” Kiriko said, standing below him.

Go bit his tongue before he could snap at his sister that she thought he’d killed someone, out of spite or out of carelessness, and that there wasn’t going to be any working this out until he’d found the real killer and proven his innocence. In the background, Nira droned on, slandering Drive as well as Mach, and casting doubt on whether or not the Kamen Riders had ever been heroic to begin with. Go covered his ears with his hands and stared at the ceiling.

“We’ll be back,” Kiriko said, hesitant now, but Go kept ignoring her.

The sound of the door opening and closing, footsteps and the swish of clothing, and finally the beep of the biometric scanner faded into silence. Go remained still. He couldn’t hear if anyone had stayed, but if Krim was still attached to the mobile stand, then he wouldn’t have made noise Go could hear, and Go wasn’t about to blow his first chance at escaping.

The ceiling gave him his first idea; the lift tunnel for Tridoron wasn’t that high, and it had rough sides Go was fairly sure he could climb, if he could get the doors open. He glared at them for a while, trying to remember the activation sequence, until another idea occurred to him. In the event of a fire, even the biometric locks should automatically open.

* * *

Chase turned the Drive Driver over in his hands, its outlines familiar and subtly wrong. Modifications had been made, from the version he’d been given, and he could see where the design had been improved. It wasn’t quite as rough as the device he’d used, a little more streamlined. He kept expecting the same bumps and ridges, tripped up when the Driver was smooth under his fingertips instead.

“I don’t know whether or not this will work,” Krim had told him, when Chase had first buckled on the Driver and accepted Tomari Shinnosuke’s Shift Car. In theory, Chase was an acceptable candidate, since he was the original user of the prototype system. In practice, nothing was ever quite so simple.

“Does Tomari Shinnosuke agree?” Chase had asked, and at the affirmative answer, he had slotted the Shift Car into the Driver and the transformation had washed over him. The motions felt familiar, with the peculiar ripple of a once well-known experience returning after so long that the original memory was all but forgotten. It triggered a cascade of information that had been buried, driving him to his knees.

Heart stood over him, his vision blurred and full of static, damage reports from nearly every system. Chase was at the mercy of his enemy, expecting death or worse, but Heart had looked at him with something resembling compassion before he began the terrible process of burying everything that Chase was.

The replay faded, leaving Chase disoriented at the vertical shift in position, pavement digging into his palms and the sky above his back. He was facing down, not up, and Krim was calling his name. “I’m fine,” he said, standing, and Krim’s digital face grimaced.

“This must be difficult for you,” he had said, and it was the first time any of Chase’s creators had acknowledged that he was more than a machine to follow instructions.

Chase had released the transformation, feeling the armor fall away into nothing, and given no answer. The city spread below him now, thousands of glittering lights clean and pure and untainted by doubt. Krim was silent, face dark, and Chase didn’t know if he was aware of his surroundings or if he had simply chosen to give Chase the illusion of privacy. He hadn’t meant to take the Driver with him, but he’d found himself carrying it in what felt like the most natural gesture in the world.

“Am I too late?”

Heart’s voice was whisper-soft and perfectly clear. Chase set the Driver down at his feet and turned around slowly.

“I came to return this to you,” Heart said, and held up the Shift Car Chase had used as Proto-Drive. The black and purple shape was barely visible, nothing more than a shadow in Heart’s pale hand, but Chase knew it intimately. “I wanted you to come home.”

“I don’t have a home,” Chase said, and his voice trembled. The human Krim had created him to be used as a tool, and the Roidmudes had broken his mind and memory to do the same.

“I don’t want to lose you,” Heart said, stepping closer. He stopped, just out of arm’s reach, with the Shift Car outstretched.

“You don’t want to lose any of the Roidmudes,” Chase said. “You mourn their deaths, but you still send them to be slaughtered.”

“I don’t wish for their deaths,” Heart said, and Chase closed his eyes briefly. “But we must all play a role,” Heart continued, “and I will save as many of us as I can.”

“It’s not enough.” Chase felt his throat close off, the words refusing to come. “I don’t know what to do.”

“Come home,” Heart said again, but he dropped his hand to his side. “You’re torn.”

“Yes.” The disappointment on Heart’s face struck Chase like a blow; he knew it was sincere, knew that Heart would feel sorrow at the loss of a comrade, and that Heart would still send the Reapers and others to take Chase down, if he fought with Tomari Shinnosuke and the humans. No matter how much it hurt, Heart never wavered from his purpose, and Chase couldn’t reconcile Heart’s genuine empathy with the unrelenting drive to accomplish his goals.

“I will welcome you, if you return,” Heart said. Unspoken went the corollary; that Heart would now try to kill him, if he saw him on the field. Heart might even try to hunt him down and have him assassinated, if Chase didn’t ally himself with the humans, simply because Chase was a loose end, and Heart couldn’t afford loose ends. Even that knowledge did nothing to diminish the warmth in Heart’s words.

“I know,” Chase said.

Heart placed the Shift Car on the ground and walked away, dropping over the side of the building with economical grace. Chase waited for a moment, until the sounds of Heart’s departure had faded, and picked up the Shift Car. The memory of Proto-Drive’s armor was almost tangible against his skin, and he shuddered.

“What will you do?” Krim asked softly.

“Were you listening?” Chase said, instead of answering. Krim didn’t reply, simply waited, digital face set in its neutral expression. His expectations were clear; Chase had already used the Drive Driver, already acquiesced to a task set by the humans – to retrieve Mach, before he did something irreversible, although Chase had failed in this task – and Chase thought that the question itself was a formality. “I don’t believe that Shijima Go destroyed 007,” Chase said. “Or killed the human.”

“Why do you say that?” Krim was still neutral, but Chase thought he heard an undertone of skepticism. Human speech was hard to decipher, more so when it was filtered through Krim’s algorithms.

“He saved my life,” Chase said. “He hates the Roidmudes, but he had mercy when I was dying and helpless.”

“Mach has destroyed a number of Roidmudes,” Krim said. “Having him free to act as he will is not a risk we can take.”

Chase closed his fingers around the Shift Car, unhappy and unable to identify why Krim’s explanation didn’t make sense. The little machine dug into his palm, quiet and still, a relic of his past instead of a useful piece of his present. Chase put it in his pocket and picked up the Driver. “I will return you to the Drive Pit,” he said. “I will give you my decision when I have made it.”

* * *

Reaching the driving school by train was monumentally inconvenient; Shinnosuke cursed at the city’s public transportation in the privacy of his own head more than once, wondering if the school’s placement was deliberate. “If no one can reach the place, we all have to keep taking the trains, is that it?” he muttered under his breath, searching for the bus station that would take him on his final leg of the journey. The old woman next to him eyed him with trepidation, and Shinnosuke gave her a reassuring smile.

The phone in Shinnosuke’s pocket was no less dead of charge when he arrived at the driving school than it had been when he put it in his pocket in his apartment, but he couldn’t help checking it anyway. Bad enough that Shinnosuke had been deliberately kept away from the SIU offices to give him time to recover, but he had the sneaking suspicion no one would have told him of Nira’s news broadcast if he hadn’t happened to see it. Shinnosuke had heard that the First Division had a new manager – and he’d been glad, at first – but he had yet to run afoul of the man. Kiriko had been tightlipped, leaving Shinnosuke to read between the lines.

The broadcast, though, that had been the last straw. No matter what the SIU or the rest of the police department had found – no matter what pictures had been snapped at the scene and were now circulating through every news outlet in the city – Shinnosuke couldn’t believe that Go would willingly commit murder. The initial report uploaded by the SIU had told him nothing useful, and Shinnosuke had printed out a copy just in case something jumped out at him later, but he needed to talk to the team.

The obvious course of action was to call Go, Kiriko, anyone, but somehow he’d managed not to notice that his phone battery had drained far enough to switch the device off entirely. Clearly the next best option was to go to the Drive Pit and get Mad Doctor to work on his remaining symptoms, so that Shinnosuke could find a solution to this appalling mess. It was his team, and he was supposed to be there to support them.

The Drive Pit doors, when Shinnosuke reached them after evading a never-ending parade of tangential coworkers who would have made far too much of a fuss at seeing him back in the office already, were closed. And locked. The upper door opened without a problem, showing him the dimly-lit flight down, but the inner door refused to budge. Shinnosuke hadn’t even known there _was_ a door at the bottom of the stairs; he rattled the handle, tempted to swear at it. The door was never locked; the Drive Pit was safe from discovery by being accessible from a corner of the building that was never, ever used.

“You can’t possibly have been shut down,” he said to the door. “Someone would have told me.”

“You have to use the biometric scanner.”

For a moment, Shinnosuke thought the door itself was talking to him, and then he recognized Go. “Open the door,” he said. “This isn’t funny, Go.”

“I can’t,” Go said, and it sounded like he was right on the other side. “You have to use the biometric scanner if you want to come in.” He paused. “I promise I won’t try to run out, if you do.”

“Run out?” Shinnosuke blinked, and then a little of the sludge coating his thoughts thinned and disappeared. He hadn’t even realized it was there, until it was gone, and he realized that Go had been deliberately confined in the Drive Pit. “They’re keeping you in there,” he said.

“Bingo,” Go replied, and Shinnosuke heard his footsteps move away from the door.

The scanner was part of the wall, an unassuming box, and Shinnosuke put his hand on it. It flashed red twice, and then green, leaving imprints of his fingertips glowing faintly on the screen before they faded. _So that’s what the department does with the fingerprints they collect during orientation_ , he thought, and then the door slid obligingly open. Shinnosuke stepped through, letting it close behind him.

“Yo,” Go said, perched on top of Tridoron’s hood. He sat crosslegged, not quite leaning against the windshield.

“What are you doing to my car?” Shinnosuke asked.

“Nice to see you too, Shin,” Go said. “How’s it going? You feeling better yet?”

“Sorry,” Shinnosuke muttered. “Where’s everyone else?”

“Out and about, trying to figure out how to punish me for a crime I didn’t commit,” Go said breezily, but Shinnosuke could hear the pain underneath. “You could always call someone,” Go added.

“Phone’s dead,” Shinnosuke said, pulling the decorative brick posing as a useful object out of his pocket and waving it in Go’s general direction.

“You could _plug it in_ ,” Go said, pointing toward Rinna’s workstation.

“Oh. Right.” There was always at least one charging cable hooked up near the door; today, Shinnosuke found two. He attached one to his phone and watched the screen flicker to life.

“You sure you’re okay?” Go asked, and Shinnosuke couldn’t help the bitter laugh that wanted to escape. He pushed it back down.

“I was looking for Mad Doctor,” he said. “Although I guess it wouldn’t work without the Driver.”

“Ah,” Go said. “Chase has it.”

“I’m sorry, what?” Shinnosuke sat down on Rinna’s chair, feeling vaguely unsteady and wondering if he’d somehow slipped into a dream while he wasn’t paying attention, or an alternate universe. “Chase? Mashin Chaser? Proto-Drive?”

“He wasn’t dead,” Go said. “You didn’t kill him.” He hopped off the car and made his way over toward the workstation, looking vaguely concerned.

“But,” Shinnosuke said, and words failed him.

Go leaned on the desk, peering at Shinnosuke’s face. “Maybe you should go back home,” he said. “I don’t think you’re ready to come back yet.”

Those words sparked a firm sense of denial, and Shinnosuke straightened up. “Tell me everything,” he said. “I need to know what’s going on if I’m going to help.”

“I really think Kiriko –“ Go started, and Shinnosuke fixed him with the stare he used during interrogations, the one that said he already knew most of what the suspect would say, and would come down harder if anything was left out. Go broke off, looking vaguely nervous.  
  


“Everything,” Shinnosuke repeated.

Go sighed, and started to talk.

* * *

It wasn’t that bad, Go thought, explaining to Shin what he’d missed. Shin had a right to know what was going on, and he was also surprisingly intimidating when he put his mind to it. The glare he kept fixing on Go said that he knew that Go was hiding something, but Go wasn’t about to admit to anyone that he was the one who’d rescued Chase. Not even Shin.

“You don’t know how he survived?” Shin asked at one point, and Go made himself shake his head.

“I thought it was you in the Drive armor,” he said. “But it was him.”

Shin sat back, when the recitation had finished, looking almost perfectly normal unless Go looked at the jacket and pants that weren’t Shin’s work suit and tie. It was unnatural, seeing Shin in more casual clothes, and Go’s fingers itched to find a tie. Shin didn’t look right without one. “I think you should stay here for now,” he said, and Go had known it was coming. It didn’t make the words hurt any less.

“I don’t know why I thought you would believe me, when my own sister thinks I’m a murderer,” he said savagely, and shoved himself away from the desk.

“Go,” Shin said, and stopped.

Go kept moving, crossing the Drive Pit with jerky steps and swinging himself back up onto the catwalk. “If you ask Chase for the Driver, he’d probably give it to you,” he said over his shoulder, and as if on cue, the door opened.

“Tomari Shinnosuke.” Chase’s voice echoed off the Drive Pit walls, and Go flinched. “I am glad to see that you are well.”

“He’s not better,” Go said. “He just can’t keep himself from poking his nose into things that aren’t supposed to concern him.”

“That’s not fair,” Shin said hotly. “Everything about this is my business. The Roidmudes, you, all of it.”

“Until you manage to crack your skull entirely open,” Go returned. “If you hadn’t gotten hurt doing stupid things, you wouldn’t be stuck out of the loop.”

“I was protecting you,” Shin said, voice tight, and the bottom dropped out of Go’s stomach. Shin wasn’t wrong; he’d been covering Go’s mistake, and it had all gone wrong from there.

“Like I said,” Go bit out, and turned to face the wall.

“Go,” Shin started, and broke off. Go didn’t look at him.

“Tomari Shinnosuke,” Chase said again, and then his voice dropped too low for Go to hear. The sound of rustling cloth and the clink of metal followed, and then the door opened and closed. Silence settled over the Drive Pit again, and Go tried not to feel as though Shin had abandoned him too.

 _You pushed him away_ , he told himself. _You did that. You don’t want him around, either, if he isn’t going to believe you._

“Shijima Go.”

The inflectionless voice startled Go badly; he hadn’t heard Chase at all, after the door had closed. He sat up, swinging his legs over the catwalk, and tried to calm his racing heart. “What,” he said, when he was sure that it wasn’t lodged in his throat. The word came out a little high-pitched anyway.

“I have returned the Driver to Tomari Shinnosuke,” Chase said.

“Yeah, I noticed.” Go stared down at the Roidmude, but Chase just stood there, staring up at him with an expectant expression. “What? What do you want?”

“Your sister,” Chase said. “She also says she does not understand why you rescued me.”

“When did you talk to my sister?” Go shook his head. “No. Don’t answer that. It was when you got the Driver, right? You got Shin’s Driver. You.”

“No,” Chase said.

“Of course you did.” Go climbed to his feet, leaning over the railing to glare at the Roidmude. “I saw you wearing it. Don’t pretend you weren’t.”

“That is not when I spoke to Kiriko about you,” Chase said.

Go vaulted over the railing, landing lightly on the floor before he consciously knew what he was doing, and stopped himself just before he grabbed Chase’s jacket. “How long have you been talking to my sister behind my back?”

“It wasn’t behind your back. You weren’t there,” Chase said.

“Don’t play dumb.” Go pushed a stiff finger into Chase’s jacket. “You were talking to my sister. Why?”

“She saw me in your apartment,” Chase said, and static roared through Go’s mind. When it cleared, Chase stood farther away and Go was shaking.

“She saw you when?” he asked.

“Are you unwell?” Chase moved toward him, hesitant.

“No,” Go snapped, and edged away. “She knew you were there? She knew, this whole time?”

“She asked me to give you a message, in the park,” Chase said, which wasn’t technically an answer. “She wanted me to tell you to talk to her.”

“The park? When did you – leave my sister alone!” Go found himself right back up in Chase’s personal space, close enough to touch.

“I was unaware that you dictated your sister’s personal contacts,” Chase snapped, and it was the first time Go had seen him truly annoyed. It felt good, knowing he had gotten under Chase’s apparently impenetrable skin.

“Not all of them,” Go said. He could feel his heart pounding against his ribs, pushing the anger and excitement through his veins with every beat. “Just you. Because you’re a Roidmude, and she doesn’t need to associate with something like you.” A hollow sensation grew, with each word, worming its way under the heady feeling of finally putting the Roidmude in its place until the enjoyment was nearly gone, and Go didn’t understand why.

Chase’s eyes narrowed, pale violet glittering. “You humans make no sense,” he said.

“At least we’re not trying to destroy the world,” Go snapped, trying to regain the sense of victory. It was entirely gone, leaving behind a feeling of regret.

“The Roidmude plan is only to remove humanity, so that we can survive,” Chase retorted, and he’d gotten closer to Go. “If humans weren’t so bent on destroying us, we would be content to live in peace.”

“Lies,” Go said, leaning forward to use his slight height advantage as best as he could. _Stupid boots making him taller_ , he thought irrelevantly, and Chase closed the distance between them. His lips were soft and surprisingly warm, and Go had a brief moment of frozen shock before the realization that he wanted this – had wanted it since the moment he’d laid eyes on Chase – swept over him. In that instant of motionlessness, Chase pulled back.

“Shijima Go,” he started to say, and Go knotted his fists into Chase’s jacket and yanked him closer again. Once wasn’t enough, would never be enough. _It will never be enough_ , he thought he heard in the distance, words lost in the weight of Chase’s body pressed against his, and Go wanted him closer. The ground was moving under his feet, and he was dizzy with Chase’s hand tangled in his hair, and Go couldn’t stop the moan of pleasure and relief.

The impact of the wall against his back jarred him out of the moment, and Go came back to his senses. Horror and regret, desire and aching need, a mad swirling conflicting riot echoing his own mind asking him what the fuck he thought he was doing. Go shoved Chase away, scrubbing his mouth with the back of his hand. It stung, tender and swollen. Chase staggered, righting himself with a look of confusion.

“Have I done something wrong?” he asked.

“No!” Go said automatically, and then corrected himself. “Yes!”

Chase tilted his head to the side. “I do not understand.”

“You can’t – you can’t just do that!” Go snapped. The wall held him up, a solid support, pushing against the roiling in his stomach and pooling heat in his groin.

“Because I am a Roidmude?” Chase asked, and there was an edge of fragility to the question. Go opened his mouth to take that moment of vulnerability and use it to smash Chase to pieces, and he couldn’t do it. He slid down the wall, pulling his knees close to his chest.

“No,” he said. “I can’t explain it right now, okay. Just. Just go away.”

“I don’t want to,” Chase said, and Go looked up.

“If you won’t leave, then I will,” he said, and he had completely forgotten that the door was locked for him, and only for him. He hit it, accomplishing nothing but a stinging pain in his knuckles and a dull ache in his wrist. Chase took his hand, tracing the knuckles and Go couldn’t stop him. His fingertips were smooth, touch surprisingly light.

“There is no damage,” Chase said, and Go finally pulled himself together enough to yank his hand away.

“Just leave me alone, okay,” he said. “ _Please_.”

Chase finally went, the door sliding shut behind him. Go hit it again when he was sure Chase was gone, over and over until the skin of his knuckles split open. The pain did nothing to clear his mind, and the red sliding over his hands just reminded him of the human he’d found dead. Nausea settled in the pit of his stomach, finally displacing the heat, and Go couldn’t just wait around in the Drive Pit for someone to decide his guilt or innocence.

 _What about Chase?_ his mind taunted him, apparently more worried about kissing a Roidmude than the fact that he had been falsely accused of murder, and Go told it to shut up. “It doesn’t mean anything,” he said out loud, and ignored the sinking feeling in his heart as he said it. “It doesn’t,” he repeated. “It was a mistake and it won’t happen again.”

* * *

“So he didn’t do it.” The last traces of doubt faded away, leaving an expression of relief on Tomari’s face that mirrored Kiriko’s feelings. “Thank – everything.”

“I don’t want to believe that he did.” Kiriko bit her lip. She wasn’t technically supposed to have access to the autopsy report; it wasn’t that it was unreachable, just that it wasn’t permitted, for a case in which she wasn’t officially involved. With her brother as the suspect, albeit not in his civilian identity, it was doubly forbidden for her to look at the file. Kiriko didn’t care. She’d printed out a hard copy, proof that her brother was innocent.

“Neither did I,” Tomari said, but they had both been willing to believe that Go had accidentally killed the human fused with a Roidmude. It left a sour taste in Kiriko’s mouth, but she hadn’t been able to shake her suspicion. Go had changed, while he’d been abroad, and she didn’t know him as well as she once had.

“The wound looks like it was self-inflicted,” Kiriko repeated, looking at the relevant page in the report. She had covered her tracks, after haunting the server until the report had been uploaded, trying to make sure no one knew what she’d done. She thought she’d done fairly well, and that the hard copy in her hands was the only evidence of her misdemeanor. “Like Taga used his Roidmude weaponry to do this to himself.”

“That’s what it looks like,” Tomari agreed, and leaned over her shoulder. The sharpness was back in his gaze, but Mad Doctor was still in the pouch at Kiriko’s waist. Tomari would need one more session with the Shift Car before he was fully recovered. His judgement was sound again, as far as Kiriko could tell, and it was just the cracked bone that still needed to be healed. “The coroner wasn’t quite sure, though.”

“The coroner didn’t have the footage of Taga’s fused form,” Kiriko said. “Although he should have.” She hadn’t been able to find the footage on the police servers; she knew a copy of the prison’s security footage and the data from the hospital had been admitted into evidence, but when she’d gone to look for it again, it had been gone. “Someone deleted it.”

“So the Roidmudes have infiltrated the police.” Tomari sighed heavily. “At least this clears Mach’s name, and we can let your brother out of the Drive Pit.”

“It’s not conclusive,” Kiriko said, hating that she still couldn’t quite shake the suspicion.

“It’s close enough,” Tomari said, but he didn’t know Go either. He couldn’t say with certainty that Go hadn’t gone off the rails.

“There’s something else,” Kiriko said, changing the subject. The matter of how Taga had died wasn’t quite resolved, no matter what the autopsy report said. He hadn’t been suicidal, as a prisoner, and all reports had indicated that he was overjoyed to have the power of a Roidmude at his fingertips. There was no reason for him to have killed himself in such a spectacular fashion. “The mark behind Taga’s ear.”

Tomari took the hard copy of the report out of Kiriko’s hands and flipped to the relevant page. The coroner had photographed a snowflake-shaped wound, one that had barely begun to heal before Taga had died. “Nothing on the scene caused it,” he said. “The coroner’s notes say it’s at least a few hours old, with how much it clotted.”

“Which is why Rinna and Otta are examining the scene again,” Kiriko said. The SIU had taken measurements at first, but the rest of the police department had interfered with a full assessment of the scene.

“Right,” Tomari said, after a pause, and then sheepishly pulled a pile of folded paper out of the inside of his jacket. “Maybe there’s something in their preliminary report that explains it.”

“Tomari,” Kiriko said with a groan. He’d done exactly the same thing she had, she realized; pulled the initial report off the servers and covered his tracks, while he was supposed to be recuperating. She reached for the report, which she’d skimmed through the first time. Nothing unusual had jumped out at her, but she looked more closely now, with Tomari leaning over her shoulder.

“There were traces of a Heavy Acceleration Field,” Tomari said, pointing.

“Odd, since there was no one around except Go, and the Roidmude would have to know that it wouldn’t slow him down,” Kiriko said. She glanced past the data for the state of the area, and then looked back. “Wait. Look at this.”

“What?” Tomari frowned, clearly not seeing what she thought was odd.

“The temperature of the ground,” Kiriko said. “It was frozen.”

Tomari blinked. “You’re right,” he said. “That’s not an effect of the Heavy Acceleration Field.”

“It lowers the temperature,” Kiriko felt obliged to point out. The area was always colder, after the field dissipated, and the difference could sometimes help the team know how long it had been since a Roidmude had been in the area, but it had never frozen the ground before. “But not like this.”

“Mashin Chaser had a Super Heavy Acceleration Field,” Tomari said, tapping at the data. “But he wasn’t there, and even if Mach gave off distortions, it shouldn’t have dropped the temperature below freezing.”

“So there was definitely another Roidmude.” Kiriko sat down, knees shaky with relief. “And Go didn’t kill Taga.”

“You really thought he might have?” Tomari frowned at her, and Kiriko glared right back.

“You didn’t see him,” she said. “He was fixated on hunting down the Roidmude, whether or not it was fused with Taga.”

“But he’s your brother.”

“That doesn’t change anything.” Kiriko swallowed hard, willing the lump in her throat to go down. “I hadn’t seen him in three years, before this. He went off to the United States, and he might as well have fallen off the face of the earth for all I knew.”

“That must have been difficult,” Tomari said, and his quiet sympathy was enough to bring the tears to the surface.

Kiriko turned away, wiping her eyes. When she thought she had control of her voice, she spoke. “It wasn’t easy.” She turned back, looking at the autopsy report and the data collected from the crime scene as though the two together were a lifeline. “He’s never going to forgive me.”

“He will,” Tomari said, and his face was so earnest that Kiriko almost believed him.

“You don’t know him that well either,” she said, echoing her earlier thought.

“I know that he doesn’t hold a grudge,” Tomari said, and Kiriko couldn’t help but laugh.

“He’s been obsessed with destroying the Roidmudes, for reasons he won’t talk about. If that’s not a grudge, I don’t know what is.” Kiriko swiped at her eyes again. “It’s like I don’t know him any more.”

Tomari looked discomfited, hastily rearranging his expression when he saw her looking, and giving her a small smile.

“I should go tell him,” Kiriko said, taking a deep breath. “He’ll be happy to hear that we believe him, at least.” She paused. “When does the autopsy report get released?”

Tomari, who wasn’t technically connected to the case either and had no business accessing the file, tapped at the screen to pull up the report with absolutely no regard for whether or not the department would look at him askance for the intrusion. “Huh,” he said, and Kiriko turned back.

“What?”

“It’s gone.” He angled the monitor toward her, and Kiriko nearly ran across the room. “Or – it just says that it’s inconclusive. This isn’t the same file that you printed.”

Kiriko looked at the sheaf of papers in her hand. “Then this is the only proof that Go is innocent.”

“Our report is still intact.” Tomari pulled up the report uploaded from the initial Special Investigation Unit’s analysis of the scene. “It shows the Heavy Acceleration Field and the temperature differential.”

“It’s not enough to clear Mach,” Kiriko said. “Not publicly.”

“But at least we can let your brother out of the Drive Pit,” Tomari said, and it wasn’t nearly as comforting as it should have been. “And we’re sure, now, that the Roidmudes have someone inside the police department.”

“That doesn’t make me feel better about any of it,” Kiriko said. “Who do we trust?”

“The Special Investigation Unit,” Tomari said slowly. “Our information is intact. Captain Honganji set up the Drive System to begin with. We could bring Kyu and Otta in.”

“I don’t know.” Kiriko bit her lip. “How can we be sure? Otta’s part of the First Division. He’s not really one of us.”

“We can’t suspect everyone.” Tomari buried his face in his hands.

“Until we know, we have to.” Kiriko bit her lip, worrying at it in a nervous gesture she hadn’t indulged in since childhood. “Ironic, that Go is one of the people we can trust.”

“Go see your brother.” Tomari gave her a little push toward the door. “We’ll sort this out more in the morning, talk to Captain Honganji and Rinna.”

“Right.”

The faint sense of optimism lasted until Kiriko opened the doors to the Drive Pit, calling her brother’s name. He didn’t answer, and she frowned at his tendency to sulk. He was nowhere to be seen, either, and for a few minutes Kiriko thought he was deliberately hiding to be obnoxious, until she looked up to see the hatch in the ceiling jammed partway open.

“You didn’t,” she said, but Go was perfectly capable of scaling the vertical tunnel, if he put his mind to it. Just to make sure, Kiriko climbed on top of Tridoron, still sitting innocently in the center of the room, and caught the edge of the hatch. Go was nowhere to be seen, and she dropped back onto Tridoron’s roof with a grimace.

 _We have a problem_ , she texted to Tomari. _Go is missing._


	5. Pronounced Variability

_You can’t go home again._

The sentence ran through Go’s mind, repeating itself and fracturing into meaningless syllables. He ignored it, climbing up the balcony. The roof of the building behind his was close enough that all he had to do was jump to reach the third floor, and from there it was insultingly easy to reach the railing, and pull himself upwards. There was no moon; Go had seen a faint sliver hanging in the sky the night before, and counted it lucky that there would be one fewer source of illumination to give him away tonight.

The balcony door was locked, but Go knew how to slide the tip of his keychain into the gap and lift the latch. After the shoddy piece of equipment had locked him out on the balcony more than once, he’d figured out how to get back inside, instead of climbing down to the ground floor and going back through the front. His neighbors had objected, for some reason, to his shimmying down the back of the building.

The blinds were still tightly closed, and Go ducked underneath them without unpinning the edges before sliding the door closed again and locking it. He hadn’t been sure whether or not his sister would have tried to get into his apartment to search for him, through official means or as a private citizen, but the kitchen, at least, looked undisturbed. Go thought about turning on a light for a moment, but it would give him away.

“Four days,” he muttered, and then wasn’t sure it had actually been four days since he’d broken out of the Drive Pit. His phone was off, so that Shin and his sister couldn’t find him, and he’d seen that the arrest warrant for Mach was still very much active. There had been posters. Worse, he’d made no progress in figuring out who _had_ killed Taga.

A shower and clean clothes, a few hours sleep; Go rubbed his eyes. He just needed to not be interrupted, for a little while, and he would be able to figure out a new angle. He padded toward the hallway, eyes starting to adjust to the dark, but he knew his own place well enough that he didn’t think he actually needed to see.

The hot water felt amazing, almost as good as sliding on pants that hadn’t been worn for however many days straight, and Go leaned against the bedroom wall. The hoped-for epiphany wasn’t coming, no new angle popping into his mind in a less stressful environment, and Go wearily shoved himself upright. “So we’ll do this the hard way,” he said, and the odd shadow in the hallway registered in his vision a heartbeat before it spoke.

“Shijima Go,” it said, and Go nearly had a heart attack.

“Chase,” he said, when the rush of adrenaline faded enough to unfreeze his tongue. He was awake now, jittery and shaky, a pit opening in his stomach to let the rush of shock coil outwards. “How – how long have you been there?”

“I was aware of your arrival,” Chase said, and Go blinked.

“You watched me come in and take a shower and get dressed and just – just stared?” If he could stoke the anger enough, the unsettled feeling might go away, he thought, but he wasn’t as angry as he should have been at the thought that Chase had been watching.

“No,” Chase said, and a wash of humiliation followed. Go found himself grateful for the darkness; at least it would hide the burning in his cheeks.

“Then what?” he said through gritted teeth.

“Are you upset? I have been told privacy is a human rule,” Chase said, and Go barely stopped himself from groaning out loud.

“What do you _want_ , Chase?” _Maybe if he tells you what he wants, it would help you figure out what you want_ ran through his mind, except that he knew what he wanted and it was all wrong.

“Clarification,” Chase said, and moved from hallway into the bedroom. Go backed up, despite himself; Chase wasn’t hesitating, wasn’t giving Go the courtesy of personal space, and Go was almost sure that if he didn’t try to get out of the way, Chase would literally run him over.

“Clarification,” Go repeated, back hitting the wall in an uncomfortable mirror of the last time he’d been alone in a room with the Roidmude. _Yes, the Roidmude_ , he told himself. _It’s not human. You can’t think of it as human. You can’t think of him –_ “I already told you you wouldn’t understand,” he said, breaking himself out of the downward spiral of his thoughts. Chase was standing just a shade too close for comfort, almost at the right distance for polite conversation but leaning forward in a way that made Go hyperaware of the narrow space between them.

“You told me I wouldn’t understand,” Chase said. “Because I am a Roidmude, and not human, but your sister is as confused as I am, and that is not why I am asking for clarification.”

“You leave my sister out of this,” Go said automatically, the thought of Kiriko like a wash of cold water clearing his thoughts. Chase was a Roidmude, and male, and Go _didn’t want him_ , except that somehow he’d moved away from the wall.

“Did you help me because you are romantically interested in me?” Chase asked, and Go snatched his hand away as if it had been burned. He hadn’t quite managed to touch Chase, but for the second time in as many minutes he could feel his face burn hot in shame.

“No,” he ground out. “That had nothing to do with it.”

Chase tilted his head to the side. “Did it come later, then?”

“I don’t know what you’re talking about.” Go couldn’t bring himself to push past Chase, not when that would mean touching him, and he didn’t trust himself. He balled his hands into fists, arms rigid at his sides. He couldn’t step back, either; he was trapped in a cage of his own making.

“Tomari Shinnosuke has explained to me that a kiss signifies romantic interest,” Chase said, and Go found he could move after all.

“You told Shin?” His shoes were in the kitchen. Go didn’t need them. He skidded on the hallway floor in sock feet, coming to a halt right before the entrance. Chase’s boots were just barely visible, in the faint light shining through the hole in the mailbox, neatly lined up in one corner.

“I did not tell him of our encounter,” Chase said. “I merely asked about its significance.”

“Nope,” Go said. “Nope. I can’t with this.” The concrete of the entrance was cold and a little gritty under his socks, and Chase caught his wrist before he could open the door.

“Please,” Chase said, and Go froze. He turned back slowly, and Chase let go. He was standing at the edge of the hall, sock-clad feet lined up perfectly with the edge of the entrance. There was nowhere to go but outside, if Go wanted to escape, no other avenue to pursue.

“If your actions signify romantic interest,” Chase started, words slow and careful.

“My actions? _You_ kissed _me_ ,” Go pointed out. He was fairly sure of that. Chase had started it – hadn’t he?

“I believe you are misremembering, Shijima Go.”

The door handle turned under Go’s grip, but the door itself opened inwards. He couldn’t get out that way, not when moving out of the way of the door meant stepping closer to Chase. “I’m not misremembering anything,” he said hotly, just a few beats too late, and there wasn’t enough space between them.

“It would be acceptable,” Chase said quickly, and for the first time, Go noticed that Chase’s breaths were shallow and rapid.

“What?” Go shook his head, sure he’d heard wrong. “Acceptable?”

“The pursuit of – of romantic interest,” Chase said doggedly. “As part of being human –“

“This isn’t an experiment!” Go shouted, and wrenched the door open. He stumbled around it, rough concrete digging into his feet through his socks, and he was home free. A few steps to the stairs, railings no more than a suggestion to vault over to reach the next half level until he was on the ground and running.

 _I’m not playing that game. I’m not._ Go wasn’t about to be _used_ in Chase’s new quest to become more human; the other man was – he wasn’t a _man_ , Go told himself fiercely. Chase was a Roidmude and deserved to be exterminated like all the rest, and the words felt hollow no matter how many times he repeated them.

* * *

“Little early for drunk and disorderlies, isn’t it?” Shinnosuke blinked, clutching his first mug of coffee. Which was technically his third mug of coffee, but it was the first mug of coffee he’d had at work, and he’d been up half the night trying to track down Go. None of the Shift Cars had seen him, and Shinnosuke was starting to think that if Go wanted to stay gone for a while, maybe it was best just to let him. Every time he started to say it, though, Kiriko’s distraught expression withered the words on his tongue.

“I’m going to kill him when we find him,” Kiriko said, and she’d gone back and forth between the two for the four days that Go had been missing. He hadn’t turned his cell phone on, either, that Tomari had been able to pinpoint, but Kiriko tried to call at irregular intervals anyway.

“Homicide is not acceptable,” Honganji said, without missing a beat. “Officer Tomari, Officer Shijima, your assignment.”

“Right,” Shinnosuke said. “Seriously, though, they’re starting early.”

Honganji spread his hands wide in a gesture of helplessness. “Cherry blossom season brings out the unseen and the temporary,” he said. “It is not unexpected.”

“Brings out the alcoholics, you mean,” Shinnosuke heard Kyu mutter from behind his computer screen.

“Still,” Shinnosuke said, and looked at the map. “I didn’t even know there were cherry trees here to look at,” he added.

Honganji fixed him with a flat stare. Shinnosuke pried his fingers off his coffee mug and climbed to his feet. “I’m going, I’m going,” he said. “Come on, Kiriko.”

Mr. Belt was quiet, as Shinnosuke fastened him into Tridoron, and Kiriko no less so as she climbed into the passenger seat. Shinnosuke tapped his fingers on the steering wheel, letting Mr. Belt do most of the navigation on the way to the park he hadn’t known existed, and tried more than once to break the silence. Each time, the words faded before he could get them out.

“Kiriko,” Shinnosuke managed, looking over just as Mr. Belt hit the brakes and brought Tridoron to a stop.

“We’re here,” Kiriko said, and was out of the car before Shinnosuke could say anything else. He looked around; they’d come to the edge of the city, a small area recently re-zoned from agricultural to residential, if Shinnosuke remembered the briefing correctly, and the freshly built apartment complex nestled in the rock of the buckled ridges was picturesque. It wasn’t far off of one of the main roads, either, and Shinnosuke could see why it had apparently filled up quickly.

The park wasn’t immediately visible from the road; it was a short walk up a flight of stairs and over the top of a ridge, tucked into a small hollow behind the residential building and full to the brim with blossoming cherry trees, royal blue tarps, and people. The ground was barely visible, except in strips between the tarps, par for the course for a popular cherry blossom viewing location. The trash scattered carelessly was another story.

Shinnosuke was no stranger to how rowdy cherry blossom viewings could get – between the day drinking and the subtle encouragement to volubly appreciate the transience of beauty and life itself, it wasn’t uncommon for disturbances to occur. Police involvement was a little rarer, but what was in front of him wasn’t within the scope of Shinnosuke’s experiences at all. The entire adult population of the apartment complex, as far as he could tell, was in the middle of a massive brawl.

“This is a little more than a drunk and disorderly,” Shinnosuke said quietly, and he saw Kiriko nod out of the corner of his eye. The two of them were standing at the top of the stairs leading into the park itself, and none of the revelers had noticed them yet. “We’re going to need more help.”

“I’ll call for backup,” Kiriko said, and that meant running communication through Tridoron. “You wait –“

“I’m going to see if I can break this up,” Shinnosuke said.

“Wait for me to come back.” Kiriko put a hand on his forearm and then snatched it away as she realized what she’d done. “I mean. Don’t do anything by yourself, okay? I don’t like the looks of that.”

Shinnosuke bit his lip. He could see at least one or two people at the edges of the brawl who looked as though they were down for the count, but at a distance he couldn’t tell how badly hurt they might have been. “Hurry,” he said, instead of agreeing, and the look that Kiriko gave him told him that she knew exactly what he wasn’t saying. He waited for her footsteps to reach the bottom of the stairs before he started downwards.

The knot of people surged back and forth, occasionally shaking trees as they hit each other, and Shinnosuke realized what was so eerie. There was almost no sound; none of the revelers was saying so much as a word, and the almost inaudible roar Shinnosuke had registered was the sound of footsteps and flesh hitting bone. He took a deep breath, put his fingers in the corners of his mouth, and whistled high and loud.

The people in front of him froze into a motionless tableau for a brief moment before dozens of pairs of eyes turned to look at him. A roar of human voices washed over him, and Shinnosuke scrambled backwards. The mob was racing towards him, hampered as they stopped to tear at each other in a frenzy, and Shinnosuke nearly stumbled over the top of the stairs.

“Take it!” Kiriko said, thrusting Mr. Belt into his hands and Shinnosuke had it around his waist and the Shift Car inserted in record time.

The transformation distracted the mob long enough for Shinnosuke to wade in, impervious to human-strong blows in the armor, and start pulling them apart. The people he did separate stayed that way for at least a few seconds, dazed expressions on their faces once he made them let go of each other, and it wasn’t long before the backup arrived.

Fully half of the crowd needed medical treatment, but no one was seriously injured. Shinnosuke stood off to the side, as the processing continued, and shook his head at Honganji’s question. “I mean, no,” he said, remembering that Honganji couldn’t see him over the phone. “I didn’t _see_ a Roidmude, but half the people had bruised palms.”

“It was more like a mark than a bruise,” Kiriko put in. “But it’s gone now, and most of them are claiming to have no memory of what happened.”

“It apparently involved someone from literally every apartment and condo in the building,” Shinnosuke added. “Unit party, celebrating the building officially opening and the residents moving in, all of whom arrived within the last couple of weeks.”

“Except one,” Kiriko said. “Matsumura Noriko, 23, signed the lease for the last unit yesterday and hasn’t moved in yet. The apartment itself is empty.”

“Do you think that’s significant?” Honganji asked.

“I don’t know what’s significant,” Shinnosuke said. “It’s crazy, and if there isn’t a Roidmude involved somehow, I’m handing the Driver over to Kiriko.”

“Don’t even joke about that,” Kiriko said sharply. “We’ll keep investigating, Captain.”

No traces of a Heavy Acceleration Field could be found, when Kyu delivered the scanning equipment, and Shinnosuke resisted the urge to kick it. “It had to have been a Roidmude,” he said. “There’s no other explanation.”

“Drugs?” Kiriko suggested, and then made a face. “Don’t look at me like that, Tomari. It could be some kind of cult, and we won’t know until we get the bloodwork back. Or the results from.” She glanced over at the scene, trash still scattered across tarps in disarray. “Well, that.”

“It doesn’t look as though there were any communal dishes, though,” Shinnosuke pointed out. As far as he could tell, each tarp had belonged to its own distinct group with its own supplies, the way it normally went even at a work function. “Even the drinks don’t look like they were distributed from a single source.”

“Forensics is going to have their hands full with it,” Kiriko agreed. She walked around the scene, careful not to touch anything else, scanner wand still in hand. “It’s just that a Roidmude should have jumped at the chance to engage with – with Drive.”

“That bothers me too,” Shinnosuke said, but there was nothing else they could do at the scene, and the sun was setting. “Come on.”

Shinnosuke was much less sanguine about the entire prospect when it repeated itself the next day, at an entirely different park with an entirely different population, more public than the last, and the drunk tanks were already overflowing with cherry blossom viewers before an entire park decided – again – to have a public brawl.

“It’s _ten in the morning_ ,” he grumbled, and while he didn’t think anyone had noticed him transform in to Drive to begin with, there were certainly too many people around now for him to let the transformation go. “It’s too early for this.”

“I didn’t hear back from the labs,” Kiriko said. “Did you?”

“No.” Shinnosuke glanced at Tridoron. “I’ll be back.”

“What – oh, right.” Kiriko bit her lip. “I’ve got this.” She paused. “You didn’t see a Roidmude, did you?”

“No.” Shinnosuke shook his head slowly, the gesture seeming oddly exaggerated from inside Drive’s helmet. “I saw the same marks on some of the combatants’ palms, but I couldn’t get a close enough look at them before they faded.”

“It seemed quicker, this time,” Kiriko said. “I wonder – no, go and come back, I think we need you here as Officer Tomari for this.”

“Understood.” Once in a while, Shinnosuke wondered that no one put the very distinctive car and the Rider suit together, when he drove the car both in his official capacity as a police officer and as a private citizen, but he supposed it wasn’t out of the question that someone thought he was a Kamen Rider fanboy. It would have been the least ridiculous theory he’d heard all day.

“Shinnosuke,” Mr. Belt said. “Be careful.”

“You always say that,” Shinnosuke said, only half-joking.

“There is a deeper game being played out,” Mr. Belt said. “And I can’t see the board.”

“I’ll be careful,” Shinnosuke said, but he couldn’t reassure Mr. Belt any further than that, because a frantic report of what had to be a Roidmude was coming in over the radio. “I’m on this,” Shinnosuke said, radioing through to Honganji, and spun Tridoron to meet the latest enemy.

Shinnosuke heard the third mob before he saw it, echoing off the storefronts with the sound of shattering glass. The echo of Tridoron’s engine distorted the sound, and Shinnosuke wrenched the car aside just before he drove into the edges of the mob as it spilled around a corner. He leapt out, only registering the Ride Macher’s distinctive whine after he saw Mach’s red and white stripes flash through the crowd.

“Go!” he shouted, but Mach didn’t seem to hear him. He was escorting someone through the crowd, the only person Shinnosuke could see whose face wasn’t set in a rictus of fury. They vanished into an alley and Shinnosuke couldn’t get through the mob to follow them. They caught him, tugging at the smooth surfaces of Drive’s armor, and Shinnosuke couldn’t push them aside without hurting them. He finally made it through, stumbling as he reached clear air on the other side. “Go!” he shouted again.

Instinct honed by years of training and months as Drive sent Shinnosuke rolling to the side just as Mach’s finishing strike hit the ground where he’d been standing. The ground shook, waves of dirt thrown into the air and scattered over the suddenly calm crowd. Mach catapulted away from the point of impact, handspringing in front of Shinnosuke.

“What was that?” Shinnosuke demanded. There was no way Mach had mistaken him for a Roidmude; there wasn’t even a Roidmude present, that he could see, and the docility of the crowd struck him. They weren’t calm, they were trapped in a Heavy Acceleration Field. Shinnosuke’s revelation cost him valuable seconds; in the time it took him to realize that he’d missed seeing a Roidmude on the field, Mach was charging toward him again with a wordless roar.

Shinnosuke fell back, doing his best to dodge. He didn’t know what Go was up to, and he couldn’t look for the Roidmude if he was trying not to get flattened by an ally. It took all his attention just to stay ahead of Mach’s quicker attacks, and Mach was still in his base form. So was Shinnosuke; all he had that was quicker than Type Speed was Type Formula, and he couldn’t catch enough of a break to switch Shift Cars, between Mach’s increasingly desperate strikes.

“What the hell are you doing?” Shinnosuke made the tactical decision to let one of Mach’s blows bounce off his shoulder in order to get close enough to grab him and shake him. It was a mistake; Shinnosuke’s arm went numb and Mach broke free without any apparent effort whatsoever.

“You turned my sister against me!”

Shinnosuke was surprised enough that he let Mach’s fist connect against his jaw, and he went sprawling. The one saving grace was that Mach wasn’t using any of his weapons; since he’d tried to hit Shinnosuke with his finishing move, he’d switched over to apparently just trying to beat him to death with his fists. Shinnosuke rolled out of the way of Mach’s attempt to stomp his ribs into kindling, and came up on his feet. “Go, listen to me!”

“She tried to have me arrested for something _I would never do_!”

There was pain, underneath the anger, and Mach’s form was getting sloppier. Shinnosuke grabbed him by the wrist, when he over-extended himself, and flung him into the side of a building. The wall cracked under the force of it, but Mach bounced right off. He came for Shinnosuke again, singleminded, and Shinnosuke ducked out of the way. “Mr. Belt, I need you to tell Kiriko that something’s wrong with Go.”

The moment of inattention nearly cost him again, and Shinnosuke was running out of breath. He was beginning to think Go wouldn’t stop until one of them collapsed, but at least he’d managed to angle the fight away from most of the civilian population. Go lunged toward him again, and Shinnosuke barely managed to slip aside.

“Go, I need you to stop,” Shinnosuke said, but it was becoming increasingly clear that Go wouldn’t – or couldn’t – slow down. Shinnosuke muttered a plea for Kiriko to forgive him for what he was about to do to her brother, and started fighting back.

The first time Go hit the ground, hard, Shinnosuke thought it was over. Go shook his head dazedly once, and then again, feet slipping out from underneath him when he tried to stand. Shinnosuke moved to help him, reaching out a hand. Go took it, pulled the Zenrin Shooter out of nowhere, and shot Shinnosuke in the chest.

“That stings,” Shinnosuke gritted out, rolling to the side automatically before another shot hit the smoky ground where he’d landed, and he was going to have bruised ribs when he let the transformation go. “I’m not going to go easy on you any more,” he warned, but the only answer he got was a wordless shout of rage.

“Shinnosuke, you need to look at the palm of his hand,” Mr. Belt said suddenly, and Shinnosuke grabbed the Zenrin Shooter by its barrel, redirecting the shot just before Go hit him again. Go let go of it, suddenly, and Shinnosuke staggered forward. Go kicked at him, and Shinnosuke blocked it with the Zenrin Shooter, knocking Go’s boot aside like a tennis ball. He lost his grip on the Shooter, hearing it clatter to the ground somewhere out of sight.

“All I see are gloves,” Shinnosuke said, trying to regain his breath while Mach struggled to his feet.

“His palm,” Mr. Belt repeated.

“The armor is kind of in the way,” Shinnosuke told him, and Mr. Belt’s pointed silence was enough of an answer. “Fine, fine, fine,” Shinnosuke grumbled. “Hurt him badly enough to knock him out of his transformation. Kiriko is going to kill me.”

“Not if I kill you first!” Mach barreled into him, and Shinnosuke hadn’t noticed that he’d gotten to his feet already. His back slammed into a wall, Mach’s shoulder hitting his already bruised ribs, and Shinnosuke could have sworn he heard them creak. Mach drew back a fist, and Shinnosuke moved just enough that Mach punched the wall instead of his face.

The precious seconds of time Shinnosuke had bought himself with his dodge were just enough to equip Type Formula, and Trailer Hou slid over his hand like a glove. The renewed transformation got him far enough away from Mach that Shinnosuke could start moving too quickly for Mach to see, except that when he circled back around, Mach had equipped Shift Dead Heat and was almost as quick as Shinnosuke.

“And when you’re gone,” Mach panted, “nothing will stand in the way of getting rid of all of the Roidmudes! Nothing!”

“I’m not stopping you from doing that now!” Shinnosuke protested, and had a thought. He started running, betting that Mach would chase him.

Mach did. It didn’t stop him from snapping back at Shinnosuke. “You’re protecting Proto-Zero!” he said, words almost ripped away by the wind.

“You were the one who saved his life to begin with!” Shinnosuke said, and Mach screamed again. They’d gone past the city limits, gotten onto more open roads into the foothills, and a river sparkled below them. Shinnosuke thought about throwing Mach into it, wondering if the cold water would cool down his temper.

“His _palm_ , Shinnosuke,” Mr. Belt reminded him, and Shinnosuke growled.

“I know, I know.” Shinnosuke sped up, deliberately going faster than he knew Mach could keep up with, circled back around. He threw Mach into the rock face lining the road, catching him on the rebound, and flinging him into the water below. A huge plume of water sprayed upwards, and Shinnosuke leapt downwards. The river wasn’t deep, barely a meter, with a sandy bottom. The once-clear water was full of silt, as the water pattered back downward, and Mach surfaced slowly.

The white and red armor vanished, Go floating face down in the water just out of arm’s reach and floating farther away with the current. Shinnosuke slogged forward, cursing under his breath, and grabbed the edge of Go’s hood. He tugged Go toward the shore, turning his face out of the water, unable to tell if Go was breathing or not. Blood trickled out of one nostril, the crimson against Go’s pale skin an eerie echo of Mach’s armor.

“Come on,” Shinnosuke muttered, finally reaching shore. Go sputtered and coughed, water dribbling out of his slack mouth, but his eyes remained firmly closed. At least, Shinnosuke thought, he was breathing, and he radioed for an ambulance. .

* * *

“My name is Noriko,” she said, and her face was familiar. So familiar. The sky whirled around above their heads, a dizzying array of blue and white, dipping and circling until he wasn’t sure he could stand up straight. “Thank you for helping me.”

The mob outside was mad – cherry blossom viewers transformed into half-animals, pointed teeth and claws, without a trace of sanity left in their snarling faces. Each one bore the same rictus of pain and rage, lashing out at whatever came closest until the blood fell like rain. Taga’s face flashed before his eyes, turned the wrong way on his neck, and Go swallowed convulsively. “I couldn’t –“ he started to say, and felt her hands on the Mach Driver.

Mach’s armor fell away, the transformation dissolving into nothing and leaving Go staring barefaced at the woman he didn’t know but thought he should. “Shijima Go,” she said slowly, and he snatched the Mach Driver and Signal Bike out of her hands. She brought them up to cover her face, slender fingers unable to suppress the laughter that shook her shoulders. “Shijima Go,” she said again, and the buildings around them echoed with her mirth.

Noriko – but that wasn’t her name, was it? – threw her head back and laughed, glass cracking and shattering, caught in the air in a perfect spray arcing out from each window. The buildings melted into sand, filling the streets, eddying around the shrieking mob until they were buried underneath it and Go had no idea how he’d stayed on top of the shifting tide. Noriko took her fingers off his wrist, sliding them across his palm in a gesture that meant nothing. When she broke contact with his skin, Go felt himself begin to sink.

“It’s too late for you,” she said. “It’s always been too late.”

The Roidmude that wasn’t a Roidmude, spotted like a cat with the shell of a snail thrust out of its back darted forward, zigzagging across the dunes, and spread its muzzle wide in a grin. “I’m going to help Shin,” Go heard himself say, but his palm was burning hot. He looked at it, expecting to see flames, but there was nothing. The outline of a crimson bruise flickered, and Drive couldn’t run in the sand. Go started to intercept, before the creature murdered his friend and rival, but his feet were stuck fast.

The snail-cat amalgamation cackled, sliding down the side of a hill that hadn’t been there a moment before, and Go was trapped. Purplish pink sludge encased his feet and legs, held his hands to his sides, and his palm felt as though it were on fire. Go screamed Shin’s name, to help him or warn him, he didn’t know. He didn’t think Shin had even seen the Roidmude coming, if that was what it was.

“I know you did it,” Shin said, and the hand that wasn’t burning was dripping wet. Go closed his eyes, not wanting to see it.

“It’s not me,” he said. “I didn’t do this.”

“But he thinks you did,” Noriko whispered. “He knows that you’re capable of it, that you would have done it, if you’d had the chance. Just because someone else got there first doesn’t mean you don’t have a guilty heart.”

“I wouldn’t!” Go protested, but the liquid only spread further up his arm, and the Roidmude that wasn’t kept circling. “Shin! You have to believe me!”

“You’re a murderer at heart,” Shin whispered. “It was only a matter of time before your cruel vendetta got someone else killed. You’re just lucky it wasn’t your sister.”

“You – you should –“ Go choked, gasping for air that wouldn’t come, and a kernel of rage slipped down his throat. It lodged in his chest, flaring to life, and Shin ran towards him. Shin had been the Roidmude all along, gleaming red armor hugging its spotted fur and flaking shell, and someone watching from an impossible shadow. Drive’s booted foot impacted against Go’s chest, and for half a second Go thought he saw glittering purple eyes before the pain picked him up like a rag doll and shook him apart.

* * *

The mark on Go’s palm flared brightly against pale skin, virulent red surrounding a poisonous blue. It was hot to the touch, the skin under it swollen and tight. Go tried to pull away, when Chase ran a finger along the edges of the mark, muttering incoherently behind the mask covering the lower half of his face, and Chase let his hand fall to his side. “It is a Roidmude’s mark, Tomari Shinnosuke.”

“Yeah, I know.” Tomari scrubbed a hand through his hair, leaving it to stand up in tufts all over his head. “Do you know which one?”

Chase shook his head. “A Roidmude gains a new shape with its evolution. This does not match any with which I am familiar.” He reached for Go’s wrist again, tracing the mark a second time. “It feels angry,” he said softly.

“All of the victims were,” Tomari said, and Chase blinked.

“All?” he repeated.

“They had to be put in solitary confinement,” Tomari said. “We don’t have enough space for them, but if we keep them together they try to tear each other apart.”

“Is this why Shijima Go is restrained?” The heavy bands buckled along Go’s wrists and ankles took on new significance, despite his apparent unconsciousness. “So that he does not cause harm to others?”

“Or himself.” Tomari shook his head. “His bloodwork is screwy, too. All of their bloodwork is screwy; the ones we’ve been able to test had high levels of norepinephrine and –“ He stopped. “I don’t know what that means. I don’t suppose you know what that means.”

“I do not.” Chase looked at him steadily; Tomari had called him for a reason, but wasn’t explaining what that reason was, and he was fairly sure that a hospital room wasn’t a normal place for a meeting. The sight of Go, trapped and unaware of his surroundings, was not conducive to holding any sort of conversation; as much as Chase tried to keep himself on topic, his gaze kept sneaking back to Go’s face.

“Chase,” Tomari said.

“Yes?” He was tracing the unblemished skin around the Roidmude mark, Chase realized, without having meant to do so.

“I know –“ Tomari paused and took a deep breath. “I know we asked you to help us before.”

Chase had an idea, of what was coming, and thought it was charitable of Tomari to use the subject _we_ , considering that he had had nothing to do with the previous request. He rearranged his face into the closest approximation of polite interest he could manage.

“But we – I – need your help again.” Tomari had to know what he was asking; that he was asking Chase to betray the Roidmudes who had rebuilt him and given him a home, even if they had been the ones who had taken his identity to begin with. “To help the people who’ve been affected. To help Go. We need to find this Roidmude.”

 _And kill it_ , Chase finished mentally, and found his hands clenched in fists. That made him no better than Heart, slaughtering his comrades in order to protect others, but the thought of leaving Go to suffer was somehow worse. “Tomari Shinnosuke,” he started, and Tomari snapped his fingers.

“Wait,” he said.

“What?” Chase looked around, but he was unable to determine what had caught Tomari’s attention.

“You said when a Roidmude evolves, that its form and its colors take shape, and that it can’t be predicted,” Tomari said.

It wasn’t precisely what Chase had told him, but it was close enough, and more or less accurate. Chase nodded.

“So the Roidmude that did this to Go must have evolved,” Tomari said. “Obviously. It would have had to. It was obvious from the start.”

That wasn’t a question that required an answer, and Chase stroked the skin on Go’s wrist below the restraint in lieu of speaking. It was soft and warm, but he could feel Go’s pulse beating far too rapidly. Tomari kept going.

“So if the Roidmude evolved, there must be a human partner.” Tomari slammed a fist into his open palm. “The same person must have been present at every –“ He stopped, and Chase fought the urge to look around again. Tomari was staring at the air halfway to the mostly-closed door, fingers twitching back and forth. “I would be willing to bet,” Tomari said, but instead of finishing his sentence, he was pulling his phone out of his pocket and leaving for the hallway.

Chase looked from the open door back to Go and to the door again, unsure of what Tomari wanted him to do; Tomari hadn’t even waited for an answer, not that Chase knew what answer he wanted to give. Sudden painful pressure against his fingers pulled his attention back, and he looked down to see Go’s eyes open. Go had grabbed the only part of Chase he could reach, and was clinging to him.

“Chase.” The single syllable was all that Go said, despite his mouth working as though he wanted to say something else.

“I am here,” Chase said, because it seemed as though a response was expected, and he had no idea what it was supposed to be.

“Let me out,” Go said finally, tugging against the restraints. His eyes glittered, heavy-lidded, and the mark on his palm pulsed hotly against Chase’s skin.

“I can’t do that,” Chase said. “You are not in your right mind.”

Go’s eyes narrowed, color rushing into his face, and he pulled harder. His spine arched as he struggled, but the straps held, and he finally sank back, breathing hard. “You’re going to regret this,” he said. “You and all of the rest of the Roidmudes.”

“I do not believe you mean that,” Chase said cautiously.

“Are you working with Shin?” Go laughed, low and soundless. “Of course you are. You’re working against me. He hates me. He hates me, and he did this to me, and you’re just like the rest of them, and I don’t want you to be.” He twisted again, the edges of the restraints digging into the tender skin of his wrists. “You saved my sister, and I saved you. That makes us even.” He paused, and for a moment Chase thought he was going to say something else, but the door slammed open and Tomari burst back into the room.

“Do you recognize her?” Tomari asked, thrusting his phone toward Chase, and Go snarled low in his throat. Tomari flinched, dropping the phone.

Chase caught it, looking at the picture and ignoring the byplay. Tomari dragged him out into the hallway, and Chase let him do it, although untangling himself from Go’s suddenly tighter death grip on his wrist was difficult. “This is Nishihori Reiko,” he said, handing the phone back to Tomari.

“What? No, that’s – Matsumura Noriko is Nishihori Reiko, because of course she is,” Tomari said. “I arrested her father during the Global Freeze.” He put the phone in his pocket. “Find her, and we’ll find the Roidmude.”

“I will help you,” Chase told him. “If the Roidmude can be defeated, the effects on the humans may vanish.” He couldn’t use the right word for it, couldn’t say _killed_ , even though that was the only way to be sure. One Roidmude against countless humans.

Tomari nodded, looking down at him with what Chase thought might be sympathy. “I have something for you,” he said, and held out the Mach Driver.

“I cannot,” Chase said. “It does not belong to me, and I will not wear a belt that belongs to another again.”

“What?” Tomari looked at the Driver in his hand and back at the now-closed door. Go had fallen silent, after Tomari was no longer in his field of vision, but Chase didn’t want to see his face twisted in rage again. “No, this isn’t the Mach Driver. It’s the same system, but Rinna made a copy of it for you. Just in case.”

The Shift Car Prototype fit into the Driver, but Chase thought it had been too heavily damaged to use. He removed it. “Can this be repaired?”

Tomari took it with both hands, handling it carefully. “Maybe,” he said. “Do you want me to ask Rinna to try?” Chase nodded wordlessly, and Tomari placed the broken prototype into a carrying case. “She made this, for you to transform,” he added, and handed Chase a Signal Bike. “The Signal Chaser.”

“It looks like the Ride Chaser,” Chase observed, turning the small object over and over in his hands.

“Yeah, that was on purpose.” Tomari grinned, but it didn’t reach his eyes. “Can I call you, when we find Nishihori and her Roidmude?”

Chase nodded again, and Tomari vanished down the hallway. Chase was left behind, staring at a closed door with a Driver in one hand and a Signal Bike in the other, unsure if he wanted any of it. “I was built to protect humans,” he murmured. The Driver felt different, than the Proto-Drive system, almost entirely unfamiliar, and Chase stuffed it in his jacket so that he wouldn’t have to look at it. He could still feel it, hard against his side, and he put a hand on the closed door before he thought about it.

Go was silent, when Chase pushed the door open again, eyes closed and body lax against the disheveled blankets. The mask had been pushed aside, and Chase looked at it for a moment before maneuvering it back into place. Go didn’t so much as twitch, during the process, and Chase wasn’t quite surprised to identify a feeling of disappointment.

“I do not think you saved me because of your sister,” he said quietly, and brushed a lock of hair out of Go’s eyes. “My debt to you is another matter entirely.”

The call from Tomari took both more and less time than Chase had been anticipating; Nishihori Reiko had fused with Roidmude 050, which Chase supposed made sense. 050 had always had a twisted sense of humor, and would have been amused to have partnered with the daughter of 005’s human counterpart. The difficult part was that it was a true fusion, as had been reported with 007, and Tomari wouldn’t let Chase kill it.

“We’ve been over this,” Tomari growled. “We can’t kill the human.”

“It is no longer human,” Chase pointed out. The Driver was belted around his waist, and the Signal Bike was in his hand, and the Roidmude’s crimson skin was beaded with the rain falling steadily from a darkly overcast sky. Thunder rumbled in the distance.

“You don’t _know_ that,” Tomari said. “We don’t know anything about how this works. It could be possible to separate them. Taga was human when – when he died.”

“Or they could have separated after death,” Chase said. “There is no other way to counteract the effects of the Roidmude’s mark.”

“You can’t possibly tell just by looking at it,” Tomari snapped.

Chase didn't have to answer that. He slid the Signal Bike into the Driver, and Tomari grabbed his arm.

"Wait," he said, other hand pressed against the side of his head. "Go ahead."

Chase couldn't hear the transmission, and there was only so long the Roidmude was going to stand there and wait for them. It had been laughing, when they'd first shown up, and now it was visibly impatient.

"Something the matter?" it called, voice an amalgamation of what 050 might have sounded like if it had evolved on its own and the voice of a human woman. "Cat got your tongue, perhaps? Or other parts?"

Chase shook off Tomari's hand and slid the Signal Bike into the Driver. The armor settled over his skin, too light in some places and too confining in others, fundamentally wrong because it was neither Proto-Drive nor Mashin Chaser. He shivered for a moment and then the Roidmude was on him. Chase dodged the first strike, ducking underneath it. The new armor was quicker than he'd anticipated, and he overcorrected. The Roidmude laughed again, Nishihori's voice overlaid with 050's, and Chase climbed to his feet.

"Be careful," Tomari called. "And Rinna thinks that if we can bring the fused Roidmude back to her, that she can figure out how to separate them."

"That may be difficult," Chase said. He wasn't entirely sure Nishihori wasn't trying to kill them both.

"Your armor has an axe. Don't use it," Tomari said, and switched forms. The new armor was significantly slower than Type Speed, and Chase didn't immediately recognize it. "Keep her busy," Tomari said, and Chase did his best to comply. Nishihori could hear Shinnosuke just as well as he could, and redoubled her efforts to reach Tomari.

"How does it feel?" she asked, and she wasn't speaking to Chase.

"Peachy," Tomari said, and Nishihori actually stopped moving.

"You killed another Rider, and that's it? That's all you have?" She shook her head. "I knew you were a bastard when you arrested my father, but this? This is so much worse than I thought."

"He's not dead," Tomari said, almost absently, and a cage of light trapped Nishihori where she stood. "You're going to help us cure him, along with everyone else you infected."

Nishihori flung herself at the bars of the cage, bouncing back to the center with no discernable effect. "He can rot in hell, just like the rest of them," she snarled. "A blemish on your record as payment for what you did to my family."

"I arrested your father because he was guilty," Tomari told her, and Chase had no idea how he was going to confine her, much less keep her accessible for experimentation.

"Tomari Shinnosuke," he said. "I believe a piece would be sufficient for the purposes of analysis."

"A piece?" Tomari turned toward him, and Chase hefted the axe he'd finally managed to locate.

The axe told him to wait. Chase frowned at it, unsure if it was some sort of joke, until it apparently finished charging and gave him the go-ahead. "Release the cage," Chase said, and Tomari actually complied. The axe had enough power to destroy the evolved Roidmude entirely, but Chase directed its power to break off part of the Roidmude's body instead. Nishihori howled in pain, folding in on herself, and Chase thought perhaps she could be confined after all.

"I didn't mean to mutilate her," Tomari said, but he took the part that Chase held out as an offering.

Chase, for his part, felt he was mostly finished, and it was Tomari's problem to confine the evolved Nishihori-Roidmude fusion now that it was more or less incapacitated. He waited, until the scene was clear, and he was the only one left standing in the rain. Tomari had tried to invite him back to the Drive Pit, or anywhere, but Chase didn't want the company. Once the last of the sirens had faded and the flashing lights were gone, he turned around. "You can come out now," he said.

Medic walked into the street, feet damp and the rest of her dry under an elaborate umbrella. It matched her clothing, water sliding around its decorative edges to glisten in the dim light and further obscure her face. "Heart thinks we should let you live," she said.

"Heart does what he thinks best." Chase released the transformation, feeling the armor fall away, and put the Driver back inside his jacket. The Signal Bike remained in his hand, hard edges cutting into his palm. "As must you."

"You were never one of us," Medic said, and walked closer. It should have been a delicate movement, given the human image she'd chosen to adopt, but it was predatory. She was sure-footed, each step economical, and Chase was fairly sure that if she tried hard enough, she could kill him. "We should never have saved your life to begin with."

"You didn't save my life," Chase told her, and the words rang true. It was the first time, since waking inside an apartment after he'd been sure he was dead, that he didn't second-guess his memories or himself. "You didn't save my life," he said again, almost wonderingly, and followed the thought to its conclusion. "You stole it."

Medic blinked, surprised. "We gave you back what the humans who made you took away," she said.

"You subverted my core programming and erased my memories." Chase balled his hands into fists. "If you'd really believed you were helping me, you wouldn't have lied to me." He wondered, dimly, if this was what anger felt like, but Medic was stalking toward him and Chase had no time to pursue it.

"You're a loose end," Medic hissed. "Stay out of our way, or I will make sure you die, no matter what Heart wants."

"Why not interfere with Nishihori Reiko?" Chase couldn't help asking.

"Because she hated Roidmudes as much as she hates the police," Medic said. "She wouldn't have stopped there."

"So you threw 050 away as if he were nothing," Chase said. "Even though he was one of you. One of the hundred and eight."

"He wasn't close enough to being part of the Promised Number," Medic said, and Chase had no idea what she was talking about. "The Neo Viral Cores are an evolutionary dead end."

“Is that how the humans fuse with a Roidmude?” Chase asked, and Medic made a disgusted face before stalking off without another word. Chase stored the information, in case it became useful later, and wondered if his own Viral Cores had been modified, or put to use. He hadn’t meant to leave them behind, but he hadn’t seen them, since he’d been revived. Chase shook his head, dismissing the thoughts as pointless.

_Medic and Heart think I have chosen to stand with the humans. So does Tomari Shinnosuke._

Chase started walking, slowly, unsure of his direction. His actions spoke more clearly than the indecision he felt; at each turn, he allied with the humans who had created him, each act seemingly insignificant and a perfectly reasonable choice to stop a greater wrong. He still felt conflicted, but the overarching pattern was undeniable. He stopped at a corner, the road branching into multiple directions from a non-standard intersection. There was no straight line forward, and he could not choose which way to go.

* * *

Anger rolled beneath the surface, a vast sea of potential lying just within reach. It surged unpredictably, the heat against his palm building with each swell until it was almost painful. It felt good, burning him clean of misconceptions and useless thoughts, leaving him pure in purpose. It told him who he couldn’t trust, that the only person he could rely on was himself, until he’d killed them all.

Go closed his eyes, focused on muting the flood to a dull roar. The mark on his palm faded, edges nearly translucent, skin smooth to the touch. Without looking directly at it, it was impossible to tell that it was even there. He smiled at the nurse removing the line from the inside of his arm and obediently pressed on the bandage left in its place.

“Are you sure he’s all right?” Kiriko wasn’t asking because she was concerned about him; she was asking because she thought he was going to hurt someone else. Go made himself sit still, kept his expression bland and polite. “He nearly drowned.”

“His EKG has been normal,” the nurse told his sister. “His lungs are clear, and his saturation has been over 97% on room air for the last several hours. He’s good to go.”

Kiriko bit her lip and gave him a worried smile. Go smiled back. “I feel fine,” he said.

“You always say that,” Kiriko told him.

Go uncurled his fingers, one by one, keeping the motion as unobtrusive as possible. “Shin pulled me out of the water before anything happened,” he said. “Nishihori is in custody. Look, everyone else is pretty calm, right? I’m good.”

“Still,” Kiriko said, and Go pushed the flare of rage down.

“There’s no reason for me to take up space here that someone else needs,” he said. “I signed everything. You signed everything. If anything happens, I come back. It’s fine.” He spread his hands wide, forgetting for a moment that the visible marker of the Roidmude’s incitement of violence was burned into his skin. He recognized his mistake when Kiriko looked at it, but her mouth softened instead of turning into the straight line that had always meant he was in trouble.

“I guess,” Kiriko said, and Go risked a glance at his palm. The mark was still faded and patchy, as if it would flake off if he washed his hands thoroughly enough. He bounced to his feet, channeling some of the energy singing through his veins, and cartwheeled through the door. “Look where you’re going,” Kiriko said, with a very familiar tone of asperity. It was almost normal.

“I knew no one was there,” Go said, tucking his hands behind his back and grinning.

“No, you didn’t.” Kiriko sighed. “Come on.”

“I’m good from here,” Go said, outside the front door. He’d spent far too long trapped already, heart beating a too-rapid staccato rhythm against his ribs, nominally within normal limits but still quick enough that he felt as though it would break through his skin if he had to spend another minute caged and confined. It wasn’t the potential injury from the near-drowning that had kept him under lock and key, after Shin had thrown him into the water and he’d passed out below the surface; the contagion from Nishihori Reiko and her Roidmude partner had been the point of concern.

Bit by bit, Go had dragged himself out of the morass of fury and paranoia. Blind rage would do him no good, he’d realized, as the anger crystallized into a cold mass pressing against his chest. It cracked into heat, if he let it, but if he could harness it, it would give him strength. He would not become a mindless victim, like all the rest of the Roidmude’s targets. He’d worked too hard for that.

Kiriko studied him for a moment, sunlight washing out her face and glowing a rich brown in her eyes, and Go cut her off before she could do more than open her mouth. “Seriously, I’m okay.”

“The warrant,” Kiriko said, brows drawing unhappily together.

“You showed me the report.” His voice caught on the edge of the anger, the waves surging nearly out of control before Go forced them back. “I know it wasn’t me. You and Shin know it wasn’t me.”

“The digital copy was altered,” Kiriko reminded him. “Someone inside the police force –“

“Then I’m safer if I’m not in police custody,” Go interrupted. “If there’s a traitor – or more than one, or just someone who’s been compromised – then I’m safer if I can look after myself. Especially if no one knows who Mach is.”

She wasn’t entirely convinced, he could tell, but she wasn’t going to try to cage him again, either. He followed her to the parking lot anyway, demonstrating that he trusted her, although he knew there was no way he was going to put himself under the control of someone else. Even his sister. “Let me give you a ride,” she said. “Your bike is at the Drive Pit.”

 _It’s a trap!_ The words howled across the inside of his skull, and Go barely stopped himself from demanding to know exactly what she thought she was doing. “I’ll pick it up later,” he said instead. “I just want to walk around for a while.”

“I’ll drop you off at the train station,” Kiriko said, and Go figured he could leap out of the car at a stop light, if she started going the wrong way. It wasn’t as though she could lock him in the front seat.

“Okay,” he said, and his breath didn’t catch in his throat as he buckled himself into the van.

Go waved at the back of the van from the front of the station until it vanished into traffic and he was sure his sister couldn’t see him, and then he started walking in the opposite direction. The mark on his palm spread warmth through him, a counterpoint to the heat of the sun beating down on his face, but he still felt cold. The chill breeze was unseasonable, for nearly May, the dampness of the air only letting the cold sink through his clothes and into his bones until he was nauseous with it.

The Mach Driver sat heavy in his pocket, its presence a hard-won concession comforting in its very weight and solidity. Go wrapped his fingers around it, tracing the smooth surface, and tried to think. He hadn’t come up with a way to clear Mach’s name, hadn’t been able to stop Nishihori, but the dozens of Roidmudes waiting in the wings – that was a problem he could start to fix. “The source,” Go murmured, and changed directions.

The Signal Bikes, in theory, could accomplish the simple task of finding Chase. Go pushed away the fluttering in his stomach and told himself that he was only after information. He set the little machines to searching and tried to piece together everything he knew about where the Roidmudes might be hiding. There wasn’t a pattern to how and where they showed up, that was the problem.

The phone ringing in his pocket took Go by surprise, after what seemed like only a few minutes, but the sun had dropped much closer to the horizon while he wasn’t paying attention. He fished out the phone to see an unfamiliar number pulsing across the screen. He answered it anyway.

“Shijima Go.” Chase’s deep voice echoed across the connection, in no way dimmed by the tinny speakers and slight crackle of static.

“I need a favor,” Go said. “Can you meet me?” He didn’t expect Chase to say yes at all, and it was with a vague sense of unreality that he found himself staring at Chase across a cup of terrible coffee less than an hour later.

Chase’s hands were wrapped around a glass of ice water, a brightly colored curly straw incongruous against the backdrop of the glittering purple jacket. Go took a sip of the coffee and then wished he hadn’t; it was bitter and burnt, coating the back of his tongue in regret. Chase simply looked at him wordlessly, waiting for Go to make the first move.

“Tell me where the Roidmudes are,” Go said, shoving the words out without preamble. If he didn’t, he thought he might say something else entirely.

“Excuse me?” Chase looked honestly baffled, and the ice shifted in his glass with a soft clink.

“Heart and the others,” Go said. “Tell me where they’re hiding.”

“If you approach them alone, you will die.” Chase took a sip of the water, through the straw, and Go had the sudden urge to knock it out of his hands.

“That’s none of your business,” he snapped.

“I do not believe your sister would appreciate my assisting you in such an endeavor,” Chase said, and Go balled his hands into fists.

“My sister is not my keeper,” he said, and it took real effort to keep his voice even.

“I also do not wish to see you hurt,” Chase said, and Go felt as though he had been punched in the gut.

“You don’t need to _worry_ about me,” he said, when he got his voice back. “I’ve been a Rider longer than you have. I know what I’m doing.”

“That statement is inaccurate.” Chase sipped his water again, and this time Go pulled the straw out of the glass and flung it on the ground.

“Don’t patronize me,” he snapped.

Chase lifted his chin in a very human gesture, eyes sparking. “I was the first to use the prototype Rider System,” he said. “Before either you or Tomari Shinnosuke transformed.”

Go blinked, and then blinked again. “You’re not wrong,” he said, and he would have gone on to explain that just because Chase had been the first Rider, it didn’t mean he’d been a Rider longer. Not when he’d been Mashin Chaser for most of that time. The expression on Chase’s face took the wind out of Go’s sails, though, a faint hint of pleased gratification.

“You acknowledge me as a Kamen Rider?” he said, and there were layers to the question Go couldn’t even begin to parse.

“Aren’t you?” Go asked, waving his hand at the copy of the Mach Driver tucked into Chase’s jacket. It was just barely visible, but Go knew what to look for.

“I had not,” Chase said, and fell silent. “I did not think I had made a decision,” he said after a moment, voice low, and Go snorted.

“You came when Shin called. You came when I called. You have the Mach Driver. I think your decision is pretty clear.”

“There is a pattern,” Chase said, as if he were acknowledging an observation without agreeing with it, and Go rolled his eyes.

“Look, you can call yourself a Kamen Rider or not, but tell me where Heart is.” He leaned forward, willing Chase to give up the information; Go knew he had it, and it shouldn’t matter, not if Chase had picked the human side.

“I –“ Chase’s phone lit up, and despite Go knowing that Chase had called him from one, it was still disorienting to see him pick it up. The case was purple and glittering, and Go had missed that particular detail somehow when Chase had laid the device on the table between them. “Yes?”

Maddeningly, Go could glean nothing relevant from Chase’s side of the brief conversation. He stared, when Chase disconnected the call, and Chase simply looked back at him. “Well?” Go said finally.

“My assistance has been requested,” Chase said. “I will give it.”

“Roidmudes?” Go asked.

Chase gave him another quiet stare.

“Look, if you’re going to help, I should go, too,” Go said, even if he was still pissed off at Shin for believing he would kill a man and arresting him for it. Roidmudes were worse.

“Follow me,” Chase said finally, and Go grinned at him.

The field was a mess, when Go pulled up behind Chase, a dozen lower-level Roidmudes without evolved forms surrounding Drive. Nishihori, with her fused body, had broken free of whatever confinement the SIU had put her in, and yet another fusion-evolved Roidmude was racing toward Drive from behind. Go had the Driver around his waist before the Ride Macher came to a stop, shouting out the transformation catchphrase over the sound of his brakes screaming.

The new fusion Roidmude went down under Go’s overclocked assault, spinning off to the side and bouncing back to its feet without missing so much as a beat. It cackled, flinging one arm dramatically wide, and the sound of screams echoed. Go noticed for the first time that the Roidmude assault was, incongruously, in the lobby of a massive bank, and that there was a crowd of trapped civilians.

“I don’t think so,” he said, and then he saw that Kiriko was getting them to safety. She was hampered by the Heavy Acceleration Field, able to move freely through it but only able to pull out the potential victims one at a time. “Well, then,” Go said. “Better make her job easier.”

The new Roidmude sprinted toward Shin, and Go stamped his foot in frustration. It was a poisonous red, the same shade as Nishihori in her fused state, and Go couldn’t help but feel the mark on his palm burn again. He let it fill him, the anger making his feet lighter, and he slammed Shift Dead Heat into place as he chased after the Roidmude.

“Opposite of open!” it sang at him, when he tackled it to the ground, and Go found himself temporarily frozen. The chains burst apart as he strained, ricocheting in every direction until they were caught in the Heavy Acceleration Field to hang in the air. Go laughed, darting toward the Roidmude again.

“Let me,” Shin said, as Go flung Tomarle’s signature move toward the Roidmude. It hung briefly in place, tasting its own medicine, and Go rounded on Shin.

“I’m not going to lose my fucking mind and murder it to death!” he snapped, fist raised, and Shin fell back slightly.

“I can separate them,” Shin said, his voice even and calm. “Just hold them in place.”

“That’s what I thought,” Go said, and slammed the Roidmude into the ground for good measure. Chase was struggling with Nishihori, off to the side, but for some reason, Shin wasn’t worried about Chase accidentally killing her. “Why aren’t you worried about _him_?”

“What?” Shin paused, in the process of whatever it was he was doing that would separate the Roidmude from the hapless human it had fused with, and the Roidmude broke free of Go’s restraints.

“Goddammit,” Go said, and started chasing it again.

The base-level Roidmudes were getting in the way, despite Kiriko kicking them to the side with her weaponized boots as she dragged civilians out of range of the Heavy Acceleration Field, and they were hampering Go’s attempts to rectify Shin’s mistake. No matter how many times he hit them, there was no end, and he could feel Shift Dead Heat burning through what little control he had until Kiriko screamed and he looked over to see her swinging in the grasp of a Roidmude he’d never seen before.

“Put my sister down!” Go dropped the base-level Roidmude in front of him and ran forward. The new enemy chuckled, low in its throat, and the sound sent ice ricocheting through Go’s blood. The heat of rage flickered and died, and he stumbled to a halt with pain searing out of the mark on his palm. “Put her down!” he said again, but his voice cracked.

“She’s delicious,” the new Roidmude said, and Kiriko slammed her heel into it. It staggered just enough for Go to see the number plate on its chest.

“001?” he said, and heard Shin gasp.

“Heart wasn’t the first?” Shin said, and Go groaned out lout at how badly Shin was missing the point.

“I told you,” Go said, and while the Roidmude might have been the first, it didn’t have an evolved form. It was still a base-level Roidmude. “Put my sister down!”

Bluish-white light flashed from the Roidmude’s fingertips to the back of Kiriko’s skull, and she went limp in its grasp. Go screamed, racing toward it, and it dropped Kiriko as if she were an afterthought. She tumbled to the ground, boneless, and Go leapt over her to slam into the Roidmude. It stumbled back, and then Go was whipped around and sliding down a wall. Plaster dust rained down from above him, and Go climbed to his feet.

“You won’t catch me like that again,” he said, but Dead Heat was overtaxing his limbs and he could barely move.

“Kiriko,” Go heard Shin say, and the only one still fighting was Chaser. There was no way he could hold off the horde on his own, and Go could see him losing.

“Son of a bitch,” Go muttered, and forced himself to rush 001 again.

“Tomari?” Kiriko said from behind him, and 001 inexplicably failed to block the strike Go had deliberately telegraphed in order to catch the Roidmude with a surprise undercut.

“Why didn’t it work?” 001 said, but Shin had gotten Kiriko out of the way. 001 turned back to Go, unfazed by the punch to its jaw. “You’ll have to do,” it said cryptically, and a blizzard poured out in all directions. Blinding white snow filled Go’s eyes, and he swung wildly in 001’s direction. Bluish white light flashed and before Go could try to dodge, stinging pain pricked him behind the ear. It spread, pulsing into agony and dropping him into oblivion.

**Notes for the Chapter:**

> Possible posting delay for concluding chapters, by which I apparently mean the entire second half of the fic, after setting some things up and straightening others out.


	6. Exponential Growth of Error

Gray walls, gray ceiling, everything muffled into soft edges and faded lighting. He groaned, head stuffed with grayish fog, thoughts moving slowly through the murk. Pressure against his shoulder and the side of his forehead, twisting along one arm and digging painfully into his hip. Hard edges digging into his knees and feet and all he could see was grit-edged smooth.

“Well?”

It took a moment for the meaning of the word to filter through, and he blinked. Knowing the word didn’t help him, not when he had no idea what had been asked of him. He couldn’t speak, mouth dry, and swallowing was painful. “Well?” he repeated back.

“Tell me your name.” The voice was strange, an odd sense of anticipation, and he knew that whatever it wanted, he didn’t want to give it to the voice’s owner. Not that it mattered; he couldn’t answer the question anyway.

“I don’t know,” he said. A little of the space in front of him became clearer, motion in his field of vision becoming feet encased in expensive shoes – _how do I know that?_ – below neatly pressed slacks, and he finally worked out that he was lying on the floor. Or the ground. He couldn’t tell, and wasn’t sure what the difference was.

“You don’t know,” the voice said flatly, and one of the expensive shoes approached him. He thought maybe he should flinch, but he couldn’t quite remember how. The shoe dug into his ribs, and the world spun dizzyingly for a moment before settling into bright lights shining directly into his eyes. The pressure had moved to his shoulderblades.

 _Ah, I’m lying on my back._ He blinked, throat still dry. The face above him swam in and out of focus, at the wrong angle to see clearly, but he thought it was frowning. “No?” he tried.

“Unbelievable,” the voice muttered, and glanced to the side. Someone else was standing there, dressed in dark green with honey-pale hair. He knew this face, he was sure of it, and when it spoke, it almost jarred the memory loose.

“Perhaps there is no genetic component,” the second voice said, and a name swung hazily into view.

“Brain,” he said, pleased that he’d worked it out. The owner of the second voice made a face at him, irritated, and he remembered that this face belonged to an enemy.

“He’s useless like this,” the first voice growled, and the shape rippled. Pale white, edged in blue, an incongruous note jarring the harmony of the monochromatic room.

He could move after all, limbs jerky but responding, and he scrambled away from the monster until a hard surface smashed into his back. The monster flung up a hand, fingertips hollow and threatening, and blue light collected in their depths. He couldn’t go any farther, but he tried, until the blue light danced toward him and flung him back into soft velvety blackness.

* * *

“I don’t know,” Chase said again. “He wasn’t with Heart.”

The edges of the Shift Car pressed against his palm; Rinna had handed it to him with excitement when they’d returned to the Drive Pit, telling him that she’d repaired it, and then finally catching Tomari’s expression before asking what had happened.

“He took my brother,” Kiriko repeated, and her hand wandered up behind her ear. She winced as she pressed on it, expression startled as if she hadn’t meant to touch it, and Tomari approached her cautiously.

“Let me see it,” he said, and Kiriko glared.

“It’s not important,” she said. “001 took Go, and who knows what he’ll do to him.”

“If he wanted Go dead, he would have killed him there,” Chase said helpfully, but it did not have the desired effect. Neither Tomari nor Kiriko seemed reassured. Tomari threw him a flat look, and Kiriko’s face paled further.

“There’s a mark behind your ear,” Tomari said. “It matches the one on Taga, when we found him.”

“What?” Kiriko looked away from Chase. “The snowflake?”

Tomari nodded, and Kiriko pulled her hand away from the reddened skin. “001 thought it would do something; he was surprised when you said my name.”

Kiriko opened her mouth as if to speak, then glanced at Chase. “Do you know what 001’s ability is?” she asked.

“He rewrites memory,” Chase said. “He altered mine, when I was…” He couldn’t finish the sentence, and sympathy spread across Kiriko’s face. Chase didn’t understand why, and it made him uncomfortable. He looked away, but Tomari had the same expression. Chase stared at the Shift Car in his hand instead.

“If you insert the Shift Car into the Break Gunner, some of your memories might be restored,” Rinna put in, and she hastily rearranged her face into a smile when Chase glanced over at her. The sympathy was still there, still tugging at the edges of her smile, and Chase looked back at the Shift Car.

“It might give us a clue about where 001 is hiding,” Kiriko said, an edge of desperation in her voice.

“Perhaps,” Chase said. It would be old information, he did not add, and not particularly likely to be useful, but it was all he had. He couldn’t help find Go, not when all he knew was where Heart had set up his home base, and that Heart was at odds with 001. “His name is Freeze,” Chase said slowly, the memory slipping back.

“Freeze,” Kiriko repeated.

Chase inserted the Shift Car into the Break Gunner and took a deep breath. It didn’t help, didn’t give him the sense of stability that it apparently gave humans, but it seemed like the right gesture to make. He activated the Break Gunner, and its current ripped along his skin. It felt almost like being healed by Mad Doctor, the same wash of rigid pain blanketing his limbs until it centered on his core, and Chase’s knees folded underneath him.

Tomari caught him, easing him to the ground as the rush of information threatened to overwhelm him, and Chase felt his back arch against the onslaught. The earliest scrap of data spread over the surface, crowding out the rest, and he could see it outlined against the sky. Chase could see the three shapes of his captors above him, clearly, and Tomari’s breath drew in behind him in a sharp gasp.

“001,” Tomari said, and Chase wanted to ask if Tomari could see it too.

The figures rippled into their human masks, smug and anticipatory, and Chase shuddered. He knew all three of these faces, intimately, and the vision faded. He went limp, against Tomari’s sturdy strength, data singing along his skin and crackling at his fingertips until it settled. New memory jostled against old, sorting itself out, and Chase finally took a ragged breath. His chest had been still, he realized, and his eyes closed.

“Chase,” Tomari said, and Chase pushed himself carefully upright.

“I do not know where Freeze might be hiding,” he said regretfully; 001 had been with them, in the beginning, until he had broken off to pursue his own agenda and Heart had decided that he had a better way.

“That’s Defense Secretary Makage,” Kiriko said, and Chase paused in the act of climbing to his feet. She sounded distant, and after a moment he placed the emotion as horror.

“No wonder,” Tomari said.

“That bastard.” Rinna’s lips thinned, and she glanced between Kiriko and Tomari. “So that’s how he got to the police.”

“Wait,” Tomari said, and for a moment Chase thought he’d put pieces together that Chase himself had been unable to see; Tomari had the look that meant he was following a glimmer of inspiration or understanding. Chase was bitterly disappointed by Tomari’s next words. “What did he mean by Ultimate Evolution?” Tomari asked, and Chase shook his head.

“I do not know.”

“So what we know,” Kiriko said, “is that we don’t know where my brother is, that the Defense Secretary is a Roidmude, and that their goal is something about which we know nothing.”

Tomari blinked at her, nonplussed. “Sure,” he said.

Kiriko stalked over to slam her open hand into the nearest wall. “I hate this,” she said softly, and then turned around. Her eyes were clear. “Isn’t there a way to at least counter Freeze’s effects?” she asked.

“Well.” Rinna tapped a finger against her lips. “You were immune,” she said. “If the needle is still in there, we might be able to analyze it.”

“It cannot be removed,” Chase said; he knew this much, at least, about Freeze’s abilities. “It dissolves, over time.”

“That’s what Mad Doctor is for,” Kiriko said, and glanced at Krim.

“That’s reckless,” Krim said immediately. “You don’t have any of the enhancements necessary to withstand –“

“We’ve used Mad Doctor to heal Tomari’s injuries without the Drive System being activated,” Kiriko interrupted.

“That’s different,” Krim said. “This is an analysis; it’s unlikely that you could withstand the procedure.”

“How else am I supposed to help my brother?” Kiriko snapped. “Do it, Rinna.”

“Would Go be happy to hear you had injured yourself in order to help him?” Chase asked, and Kiriko glared.

“You stay out of this,” she said.

Chase took her at her word. “Call me, if you find him,” he said, and left the Drive Pit. No one followed him, and Chase wasn’t sure whether or not he felt relieved. He felt restless with the need to act, but there was no action he could conceivably take that would be helpful. “Where are you,” he murmured. _I owe you a debt_ , he thought, but there was more to his need to rescue Go; the memory of Go’s skin against his, and his certainty that Go had been trying to initiate a romantic engagement. Chase wanted to pursue it with an intensity he couldn’t explain; it wasn’t just a part of the human experience, it was part of the human experience he wanted to explore with Go and no one else. “What have you done to me,” he said, but there was no answer and Chase struggled to set the thoughts aside. It was more difficult than he anticipated.

It occurred to Chase that even if he couldn’t help to find Go, he knew where Heart and Medic were, where Brain most likely was, and if he could do nothing else, he could find out what the Ultimate Evolution was. The final purpose in Heart’s plan, in 001’s plan, the goal that they were both trying to reach from different directions.

Medic’s words rang in his ears, but Chase shook his head. Even if she tried to kill him for interfering, he couldn’t stand idly by and do nothing, and as dangerous as she was, she represented a greater chance for success than Heart did. Decision made, he climbed on board the Ride Chaser. The Shift Car went into his pocket, bumpy contours the physical representation of his new memories; Chase had known, before, that his programming had been forcibly overwritten. It was different, to remember it happening, to be able to feel the creep of blankness and the pain of new directives.

“I’m angry,” Chase said quietly, finally able to place the odd sensation wrapped around his Core. He was angry, at Freeze and Heart and Brain, for stealing his free will, and yet they were still friends and comrades. “The duty of a Kamen Rider is to protect humans,” he said, but the words didn’t make the anger dim, nor did they help him assuage the guilt he felt about turning on Heart and the others. “I have to find Medic,” he said finally, and tried not to think about how he had well and truly chosen a side now.

* * *

“This is odd,” Rinna said, frowning at her screen.

“Odd?” Shinnosuke leaned over her shoulder, but as far as he could tell, everything on the screen was gibberish. He wasn’t sure any part of it included actual words, much less legible Japanese script.

“The needle,” Rinna clarified, which told Shinnosuke nothing useful.

Shinnosuke glanced over his shoulder. Kiriko was resting on the other side of the room; that she wasn’t likely to suffer lasting damage from the data collection process had been the general consensus, but only because she’d spent so long training in an attempt to equip the Drive System. “What about it?” Shinnosuke prompted, when Rinna failed to give him any further pertinent information.

“Its interactions with neurotransmitters,” Rinna said, and that still wasn’t helpful. “You see here.” She pointed at a spot on the screen.

“Uh, sure,” Shinnosuke said, more to placate her than because he had any idea what he was looking at.

“It’s very complex,” Rinna said, and Shinnosuke grimaced. “I think – and with a small sample size, it’s impossible to be sure – the victim’s sense of self interferes with the needle.”

“Kiriko definitely has that,” Shinnosuke agreed. “You think that made her immune?”

Rinna shrugged. “It’s hard to say. But I think I know how to start constructing an antidote.”

“How can you tell?” Shinnosuke asked, and Rinna started explaining which biomarkers she thought would be blocked by the potential antidote. Shinnosuke waved his hand to cut her off, and she blinked at him. “I mean,” Shinnosuke said, “how can you tell it’s a sense of self?”

“Because it’s Kiriko,” Rinna said, which wasn’t helpful either. “Shoo and let me work in peace.” Despite Shinnosuke’s myriad obligations, he didn’t want to leave the Drive Pit. “Just take her with you,” Rinna said, exasperated.

“I don’t know what you’re talking about,” Shinnosuke said automatically.

Rinna glared at him, and Shinnosuke backed away with his hands in the air. He stumbled over the edge of the bench Kiriko had claimed, and she looked up at him in irritation. Shinnosuke gave her a weak smile, and Kiriko sighed.

“We should get going,” she said. “Find my brother.” She wavered, when she stood, and Shinnosuke reached out to steady her before he thought about it. She took his offered shoulder, her other hand pressed against her temple.

“I can –“ Shinnosuke started.

“I’m afraid they’ll kill him,” Kiriko said softly. “Or worse.”

“001 wouldn’t go to the trouble to kidnap him if they wanted him dead,” Shinnosuke said, which didn’t have the effect he’d intended.

“That doesn’t make me feel any better.” Kiriko pulled on her jacket and made for the door. “He’s the only family I have left, Tomari.”

Shinnosuke followed her into the hall, hovering close enough to offer support if she needed it but trying to give her space. From the look she gave him, he’d failed on some level. “You never speak about your father,” he said.

“Ah.” Kiriko stopped walking, just before the corridor that led into more highly trafficked areas of the driving school. “He, uh. He left, when Go was a baby. I don’t know much about him.” She gave him a tight smile. “After our mother passed away, we stayed with a cousin, until I grew up, but she didn’t talk about our father except to tell me not to ask.” Kiriko took a few steps, and then paused again. “He was – or maybe is – some sort of research scientist. And now you know everything I do.”

“I’m sorry,” Shinnosuke told her. “I didn’t mean –“

“I know.” Kiriko shrugged. “I don’t remember him, not really. Go wanted to look for him, when he was little, but after I graduated high school and we started living on our own, he stopped talking about it.”

“We’ll find him,” Shinnosuke said, and Kiriko opened her mouth, closed it again, and then laughed. “What?”

“For a moment, I thought you meant my father,” she said. “Let’s go look for my brother instead.”

* * *

“How do you feel?”

The question came before he even opened his eyes, the cadence of the words subtly wrong. He swallowed, throat dry and an awful taste in his mouth. “I don’t know,” he said.

“Go, look at me.” It was a male voice, silky and persuasive, and it brought an atavistic shiver of dread.

His vision swam, blurred shafts of light and shadow, until he focused his eyes on the incongruous shape of a tiger caught forever pacing forward. He swallowed again, less painful this time, and he had failed to notice what was right in front of him.

“That’s right,” Heart said, dark hair falling past his pale face in a curtain to frame an encouraging smile.

“I was dreaming,” Go said, because his thoughts were jumbled into near-incoherency and all he could remember was a concrete floor sprouting myriad shades of gray. The images started to settle, and he sat up.

“Slowly,” Heart said, putting a steadying hand on his shoulder.

“I’m okay.” Go buried his face in his hands, pressing against his temples. The sensation of shifting weight against the inside of his skull wasn’t painful, but it was disorienting and the fog over his memory wasn’t growing any thinner. He _knew_ Heart, knew that the Roidmude was his friend and ally, but the shiver of dread at his core refused to be silenced.

“You’ve been ill,” Heart said after a moment. “But we think you’re better now.”

“We?” Go repeated, and finally managed to take in the rest of the room. Medic lounged on a straight-backed chair, despite its narrow seat, legs crossed as she examined her nails. Brain perched on a cloth-covered table, the rich yellow a brilliant contrast to his customary dark green attire. “We,” Go repeated. He felt empty, echoes of pain in his head surfacing as every new face brought another tide of changes.

“Take it easy,” Heart said, and stepped back. “You’re going to be fine. You know who we are?”

“Heart,” Go said, looking at him. “Brain and Medic. You lead the Roidmudes.”

“Lead them to do what?” Heart asked, and there was a peculiar undercurrent of tension in the room. Go didn’t like it. Brain and Medic didn’t look as though they were paying attention to him at all, but he could read their body language and knew they were hyper-attuned to what he was going to say next.

“Try to make peace with humanity,” Go said; it was what Heart had been trying to do since the beginning. All the Roidmudes had ever wanted was peaceful coexistence, but they had been hunted down and systematically slaughtered by the Kamen Riders. Krim Steinbelt had led the charge, turning on his creations after giving them free will.

“I told you he’d remember,” Brain said, with a shaky laugh, and the tension in the room dissipated.

Go frowned and opened his mouth to ask for an explanation.

“You were taken prisoner,” Heart said smoothly. “The human police tried to turn you away from us, because your transformation system is dangerous to them.”

The flash of cold hard metal against his skin was almost overwhelming, for a moment, and Go pressed the heels of his hands against his eyes. He had been locked into a room; not a cell, but the Kamen Rider base of operations. He’d climbed a vertical shaft to escape. “They didn’t hurt me,” he said. “I think.”

“No,” Heart said. “But there is a warrant for Mach’s arrest.”

The words _armed and extremely dangerous_ ricocheted along the inside of his skull, accompanied by the vision of a press conference and a photograph of his transformed figure posing dramatically against a bright blue sky. The room swayed dizzyingly around him, and Heart held him upright until the worst of it passed. “You rescued me,” Go said, testing the words. They didn’t taste quite right, but Heart nodded.

“We brought you home,” he said.

Someone was missing, but Go couldn’t remember who it was. The vertigo was fading, leaving him drained, but at least he no longer felt as though his insides were trying to fall apart. “There’s someone else,” he said, the words slipping out before he realized he was speaking.

“Freeze,” Heart said, after a moment’s hesitation, and Go felt a stinging pain behind his right ear.

There was a scar, raised ridges painful to the touch and rough under his fingertips. Go flinched, as he brushed against its center, the barest edge of sticky fluid congealed against his skin. Heart took hold of his wrist and brought his hand back down, gently but inexorably. Go didn’t resist. “What is that?” Go asked.

“Part of what the Kamen Riders did to you.” Heart’s mouth thinned into a straight line, brows dropping down in anger.

“Drive and Chaser,” Go said, almost automatically. He could see Drive’s red armor, the color of the blood on his hands, but Chaser was almost nebulous in his mind’s eye. “They – they’re trying to destroy you. Us.”

“Chaser was one of us,” Medic said. “A Roidmude. But he betrayed us, and for that he cannot be forgiven.”

“Medic,” Heart said, and it had the sound of an old argument.

“I don’t trust him,” Medic said, and Go didn’t think she was talking about Chaser. “It’s not going to stick.”

“Medic,” Heart said again, and this time there was weight behind the word. Medic’s expression changed, and she stood gracefully. She crossed the room in a single fluid motion, wrapping her arms around Heart’s neck.

“I trust you,” she said, and Heart wrapped an arm around her waist, squeezing briefly before setting her aside.

Out of the corner of his eye, Go saw Brain’s face twisted in a jealous rage. The thought that Shin could use that information to drive a wedge between the Roidmude leadership in order to take them down once and for all felt perfectly natural for a moment, before a stabbing pain manifested behind his eyes and wiped it away. He choked off the whimper that came with it, but not quickly enough. Heart looked back at him, concern all but radiating from every pore.

“I’m okay,” Go said, his voice hoarse. “It’s fine. I’m fine.” He didn’t remember being captured, didn’t remember what the Kamen Riders might have done, didn’t remember being rescued. He knew that he’d fought with Heart before, but the memories were flickering and insubstantial. He couldn’t make his friends and comrades worry, though; he thought his equilibrium would return with time, and Heart had enough on his plate already.

“I know,” Heart said, and finally moved away from him.

Go stood, carefully, stretching the stiffness out of his limbs. It felt as though he had been asleep for a long time and was only now beginning to awaken, the room around him half a step removed and wavery as if seen through a pane of ancient glass. The sensation faded, as he prowled around the edges of the space, marking the eclectic clutter and trying to remember what he’d seen before. None of it sparked a sense of familiarity, but if the Kamen Riders had done something to him, it made a twisted sort of sense.

“My sister,” Go said suddenly. She was part of the police force; she’d been the one to put handcuffs on him, he remembered in a rush.

“We will not harm your sister,” Heart said forcefully. “She will be safe.” He relaxed, flashing Go a tiny smile. “That was one of your requests, which we are happy to honor.”

“Right,” Go said. He didn’t remember saying that, either, but the hazy feeling inside his head was hiding so much. He trusted Heart, he told himself. He had trusted Heart since the beginning.

 _Why?_ The question was silent, but Go could hear the deep voice as clearly as if it had been whispered in his ear. _Why did you save me?_

“You’re not human,” Go murmured. “You wouldn’t understand.” His eyes were closed again, pressed tightly shut, and he lowered his hands from where he had pressed them against the sides of his head. The momentary screaming cacophony had fallen silent again, and Go stood uncertainly. Heart and Medic were watching him intently, a disconcerting predatory air to Medic’s stance as she leaned forward. She saw him looking at her and it vanished, her posture easing into bored indifference.

“Are you all right?” Heart asked solicitously.

“Fine,” Go said. “Completely fine. Just a little dizzy, that’s all.”

“Of course,” Heart said, but he stayed on his side of the room.

The rest of the base of operations didn’t jog Go’s memory at all; the building was almost entirely unused, as far as he could tell, low-level Roidmudes clustered here and there in small occasional knots. Go couldn’t tell what the building had been; office space around a warehouse, maybe, he thought at one point. He couldn’t figure out where he’d been staying, either, and nothing he could remember was any help. He was reluctant to ask, not wanting to flaunt his weakness after Heart’s kindness.

“Let me show you where you sleep,” Brain said, and Go flinched hard. He hadn’t heart Brain approach.

“Sorry?” he said, once his heart had dropped back out of his throat and he thought he could speak again. His voice wavered anyway.

“You’re lost,” Brain said. “It’s all right. It was to be expected.”

“Right.” Go scrubbed his hands over his face. “Heart said – said I was sick.”

“The Kamen Riders are cruel,” Brain said, and put a hand on the small of Go’s back. It felt intimate and unwelcome, but Brain wasn’t looking at him. He wasn’t leaning toward Go, simply guiding him, and Go tried to tell himself to relax.

“Right,” he said again, and let Brain push him forward.

The small space to which Brain guided him had a cot and a desk, and his camera was missing. Go frowned. The cot didn’t look slept in, and there was a fine layer of dust around the room. Brain hovered in the doorway as Go looked around, but it didn’t ping any of his submerged memories.

“I –“ Go said, and stopped.

“Don’t worry about it,” Brain said, and Go wasn’t sure it was meant to be comforting.

“My camera,” Go said, and Brain looked surprised. “And the rest of my photography equipment. The laptop.” None of it was there, and Go had no idea where it was. “What I use to do my job.”

“You don’t need to work while you’re with us,” Brain said. “We need you to have focus.”

“Of course you do.” Go ran his hands through his hair. “Do – did I have clothes here? Soap? A toothbrush?”

Brain stared at him blankly, and then a regretful expression slid over his face so smoothly Go wasn’t sure it hadn’t been there all along. “Of course,” he said. “There was a raid, when you were kidnapped, and most of your possessions were taken. We haven’t been able to retrieve them.”

“Oh.” Go wasn’t sure how to respond to that. None of the memories were coming clear, and trying to retrieve them was giving him a worse headache.

“We’ll make sure you have whatever you need.” Brain gave him what Go was fairly sure was supposed to be a reassuring smile, but it left him cold.

“Yeah. Thanks.” Go tried to smile back, but it didn’t feel right. Brain didn’t seem to take it amiss, leaving Go alone in the space apparently designated as his despite its utter lack of familiarity. He brushed the dust off the desk, looking through the drawers out of idle curiosity. They held old office supplies, the few pens cracked and dry, and Go didn’t think anyone had opened them in months or possibly years.

 _This isn’t right_. Go pressed the heels of his hands against his eyes, trying to press back against the thought. It hurt, ripping jagged pieces away from the inside of his skull, but he couldn’t suppress it. He fumbled for the door, trying to remember where the closest exit was, but there was nothing except a maze of corridors he couldn’t find his way out of.

* * *

“Weeks.” Tomari flung the pen on the desk, and Kiriko winced as she could see the smear the tip left across what hadn’t been a pristine report to begin with.

“Three,” she said, as if the twenty-two days since her brother had vanished hadn’t been among the most agonizing of her life. _I would forgive him, for not trusting me, if he came back to us alive._

“We should have found him by now.” Tomari picked up the report, frowning at it and rubbing his finger across the ink stain. It only spread further and Tomari transferred his efforts to trying to brush the ink off his fingertip. All it got him was an ink-stained thumb, as well, and Kiriko grabbed his hand without thinking about it. 

“Hold still,” she said in response to his startled look, and rummaged for the packet of screen cleaners she kept in her desk drawer. The alcohol would take the ink off Tomari’s skin. “You were busy,” she added.

“What?” Tomari looked up, mind clearly elsewhere.

“Never mind.” Kiriko pressed the little square of disposable cloth more firmly into the pad of Tomari’s thumb than she’d intended.

“Ow,” he muttered, and took both his hand and the wipe away. “Hey, this really works!”

“Of course it does.” Kiriko closed the small box and put it back in the drawer where it belonged.

“I know it’s not like the last few weeks haven’t been.” Tomari grimaced. “Eventful.”

“That’s an understatement,” Kiriko murmured. Nira assigning them to play gofer for the First Division had been the tip of the iceberg; running across old material related to Tomari’s father’s death would have been nothing more than an unpleasant surprise, if Nira hadn’t overreacted so dramatically. When Brain had shown up – calling himself Noumi, which had made Kiriko want to strangle him – both she and Tomari had been ready to believe it was related.

The Kamen Riders are a public threat, Nira had said, pointing to Mach’s still active arrest warrant, and Tomari had snarled that it was clearly a distraction. He hadn’t been wrong, not that it mattered; an innocent girl had nearly died and only pure luck had prevented Tomari’s identity from being leaked to the public at large before he’d figured out that not only was Nira bonded to a Roidmude, but that he was the one who’d shot Tomari’s father and then buried the evidence.

“A huge understatement,” she amended. “At least Brain’s stopped pretending to be human.”

“I don’t know if that’s an improvement,” Tomari said darkly. “I almost liked it better when he was where I could see him. Like how you want to know where the wasp is, if you know it’s in the room.”

“Makage’s not going anywhere,” Kiriko offered. That had nearly been a disaster; only some quick maneuvering on Honganji’s part had kept Tomari from being summarily fired, when he’d accused the defense secretary of being a Roidmude. The one-week suspension – to be served starting tomorrow – was the lightest penalty possible, but Tomari was still chafing.

“No, but he knows who I am now.” Tomari dropped the ink-stained wet wipe into the trash. “As far as he’s concerned, I’m the wasp. Or an annoying fly. Which is the only reason I still have a job.”

“We really could have used Go’s help,” Kiriko said softly. Drive’s identity was still a secret from the general public, but the Special Investigation Unit all knew what the department really was, now. It hadn’t taken long for anyone to make the deductive leap to Chase and then Go.

“Or Makage would have had him arrested on the spot.” Tomari buried his face in his hands. Convincing the SIU that Go was not, in fact, a murderer hadn’t been difficult. Kiriko hated that he’d had to do it at all. “This is such a mess.”

“You’d think knowing who Makage really is would have led us to Go.” Kiriko found herself twisting Tomari’s dropped pen in her hands, and the ink was leaking out of the tip. If she didn’t put it down, it was going to crack and ruin her clothes. She couldn’t keep her hands still.

“When all you have to conduct an investigation is this,” Tomari said, waving his hand dismissively around the room. “And we all have day jobs that require us to be – hey, I’ve been suspended.” 

“You can’t stake out Makage,” Kiriko said, before Tomari could follow his idea to its ill-advised conclusion. “Not by yourself.”

“Kyu doesn’t technically have to be here,” Tomari said, sitting up straight. That wasn’t the takeaway Kiriko had been aiming for, and she frowned.

“You want Kyu, who couldn’t protect himself against a wet paper bag, to tail 001,” Kiriko said.

“I – well, no, not exactly.” Tomari didn’t slump back over, though. His eyes got the faraway look that meant he was cataloguing information, staring at images only he could see. He nodded once or twice, slowly. “I have some thoughts,” he said, and Kiriko listened.

* * *

The base where Heart had woken Chase – where they had spent the time between attempts to send Roidmudes out to evolve, for reasons Chase had never been able to fathom – was still empty. It hadn’t changed, not since Chase had first shown up to look for a clue. Any clue. Chase stood inside the echoing space, turning around to look for some indication that Heart had even been there. He found nothing; the space looked as though it hadn’t been occupied for years, just as it had on his first visit. And his second. And sixth. And so on.

Walking into Heart’s territory in an attempt to find out what Ultimate Evolution meant had been foolhardy at best, at least the first time, and Chase knew it. He hadn’t been able to think of another alternative. The first time, he hadn’t thought it was fortunate that no one had been there to pound him into dust, although a small part of him had been glad that he wasn’t about to die. Now, he would have welcomed a hostile greeting as a sign that he wasn’t repeating a useless action. Without much hope of a different outcome, Chase started searching again, but there was still no sign that the building had ever held the quantity of Roidmudes that Chase remembered.

Not until Chase had gone into the small room Heart had forbidden him ever to enter did he find anything at all. His breath caught in his throat; what looked like a Shift Car waited on the floor, in the farthest corner from the door as if it had been forgotten. It gleamed silver in the echo of daylight from the hallway, and Chase picked it up carefully. It wasn’t one of Mashin Chaser’s, although he’d thought for a moment that it was. Chase turned it over and over in his hands, but it was inert.

“You’re supposed to be alive,” he told it. “Were you here before? Did I miss seeing you?” He paused. “Did you hear me, the last time I was here, and come looking for me?” He was unique, among the Roidmudes, in that Mashin Chaser had Shift Cars to change forms. As far as he knew, the only other Shift Cars – or Signal Bikes – were part of the Rider System, and all of them had at least some degree of life and sapience. The device in his hand held none of the barely tangible hum that characterized the rest of the tiny vehicles populating the Drive Pit.

It was possible, Chase thought, that Tomari and his team would be able to pull information out of the inert Shift Car. He shied away from the idea. Alliance or no, he was reluctant to ask for help; Tomari had finished serving his suspension and had been fully reinstated to the Special Investigation Unit, and while Chase might have asked him had Tomari still been cut off from the police force, being more closely connected with an organization tied so tightly to Freeze was distasteful. Chase refused to consider the idea that Makage made him nervous, and put the Shift Car down. The Mach Driver sat heavy in his pocket, counterbalanced by the Break Gunner. Chase set them both on the ground in front of him, one on either side of the inert Shift Car, and sat cross-legged.

“I don’t have another lead,” he said. He didn’t think Heart would have left behind a trap; it wasn’t in his nature. Heart, for all of his maddening inconsistencies, was always direct. He didn’t play games, didn’t lie, didn’t try to manipulate those around him. If he’d left this object behind, it was an oversight, or the Shift Car was broken beyond repair and had been abandoned for that reason.

Even a broken Shift Car still might have viable information. Chase reached for the Mach Driver and then changed his mind. The Break Gunner would give him cleaner access to any data remaining on the Shift Car, even if the thought of using it made his skin crawl. Chase picked it up and inserted the Shift Car. For a moment, he thought the Break Gunner had failed to register its presence at all, and that the Shift Car truly was nothing more than an inert piece of metal.

The distinctive hum of activation spread out below Chase’s fingertips, and he tightened his grip on the Break Gunner. He couldn’t tell what the Shift Car would do until he pulled the trigger, but at the very least there was no error message coming from his equipment. Chase took a deep breath out of habit, wondered why he’d done it, and let the air back out. The Break Gunner vibrated under his hands, and Chase slammed it against his chest. The familiar prickle of activation rippled out from the point of contact. Chase nearly missed the even more familiar sensation of a coercive overlay being written across his consciousness, until he found himself standing without conscious effort. It couldn’t corrupt his programming, not after the modifications that had followed the return of his original memory, but it could lock him inside his own mind. He started to walk, with no idea where he was going. Chase didn’t fight the motor commands; he focused on trying to break control from the inside instead, hoping he would succeed before he reached whatever destination Heart had planned for him.

* * *

“Ow.” Go pulled his arm away from Brain. “You’re doing it wrong.”

“Medic,” Brain said, without missing a beat.

“I repair Roidmudes, not humans,” Medic returned, smiling sweetly and with zero goodwill whatsoever.

Go took advantage of Brain’s lack of attention to swipe the disinfectant and apply it to the nasty cut running the length of his upper arm. It wasn’t deep, but the edges felt shredded and cleaning it stung. He hissed through his teeth, which only got him Brain’s focus again.

“Give me that,” Brain said. “You can’t see what you’re doing.”

“I’m better at it than you are,” Go retorted, but the wound needed to be wrapped and he couldn’t do it with one hand. Brain wasn’t much of an improvement, but Go thought the bandage would stay in place as he bent his arm and rotated his shoulder.

“You’re going to ruin it,” Brain said, and he sounded petulant. Go couldn’t remember him whining quite so much before, and it was annoying now.

“You did fine,” he said absently. “It’ll stay.”

“Well, of course my work is outstanding,” Brain huffed, and Go tuned him out, mind drifting to the fight that had left him injured and the argument preceding it.

 _Tell me who he is_ , Freeze had said, staring at Go as though he had every right to make demands. Go – knowing perfectly well who was behind Drive’s mask – wasn’t about to stand for someone who couldn’t even be bothered to show up acting as though Go were his errand boy. If Freeze had ever acted as though the Roidmudes were friends, or even acquaintances for whom he harbored some sort of positive feelings, Go might have answered differently. If Heart had asked first, Go would have told him without hesitation.

Heart had tried, warmth and openness suffusing his face, but by then Go had been committed to the lie. Even in the face of Medic’s muttered imprecations and Brain’s barely quiet comment impugning Go’s mental faculties – _How can you possibly_ not _know?_ – Go had shrugged with a calculated lack of respect. Freeze didn’t deserve it, not when he spent all of his time manipulating the police from the safety of a government office.

Go was beginning to think Freeze didn’t care for Heart’s plan in the slightest, and even if Freeze was working toward cooperation in good faith, lies and deception would only hurt their cause. Coexistence couldn’t be built on a foundation of falsehoods. Even without Freeze’s human persona, Go had figured out that he had at least one project to which Go wasn’t allowed access, and it was high time Go stopped letting his respect for Heart’s leadership stop him from learning what that was.

The fight had stopped him, at least for the moment; Drive had shown up somewhere for some reason and Go had gone off to stop him from killing Roidmudes before they evolved. He hadn’t quite succeeded in protecting 106, and the expression on Freeze’s face as he’d learned of Go’s failure had chilled Go to the bone. There had been some other plot afoot; a case from Shin’s past and the incident that had gotten his father killed had been upended and the culprit had been the same man that had smugly told the press that Mach was armed and dangerous. The only good thing to come out of any of it was Brain gaining his Ultimate Evolution, but Go wasn’t sure how, exactly, it fit into Heart’s plan.

Go didn’t particularly care. To his disappointment, he had found that removing the officer who’d announced the warrant didn’t mean the warrant itself had gone away, and then Brain had started yammering about how he was bleeding on the carpets, as if he ever cleaned them anyway. Brain was glaring at him now, and Go hastily tried to replay the last few seconds in his head to figure out why. It was no good; he’d tuned Brain out thoroughly.

“What?” he said instead.

“You’re utterly hopeless,” Brain told him.

“Whatever.” A headache had started pounding behind his eyes, and he just wanted to be done with the conversation. Go started to put his jacket back on, but the sleeve was damp with his blood, and he peeled it back off before he stained the bandages from the wrong side. In the privacy of his own head, he acknowledged that Brain might have had a point regarding the amount of bleeding he’d apparently done. Brain did not need to hear him say it out loud, he decided. “I’m going to wash this.”

“Don’t leave it in there long enough to grow mold this time,” Brain said, and Go rolled his eyes.

“That wasn’t me,” he muttered, too quietly for Brain to hear.

“I heard that.”

Go silently informed Brain that he wasn’t the only person who had decided they wanted to play house by washing clothes, once Go had figured out that there was a functional washing machine in the basement and managed through trial and error to hook it up to a sufficient water supply. He didn’t think he’d been back for more than a few days, anyway, and clearly that wasn’t long enough for wet clothes to grow mold. Someone had been playing pranks on him. Or maybe on Brain. It was hard to say.

The machine was both empty and free of suspicious odors when Go flipped the lid open to dump his jacket in. Just the jacket seemed like a waste of both energy and water, and Go debated with himself about whether it was worth it to find something else to wash. He decided against it and closed the lid, and it echoed oddly.

“ …anything useful?” That was Heart’s voice. Heart didn’t do laundry. Go ducked behind the machine, tucked away in a corner of the maze-like basement full of half-walls and odd corridors. Very little of the space was entirely closed off, but Go was sure the partitions had been designed by a lunatic and he kept finding odds and ends he’d never seen before. None of the space looked as though it saw significant traffic, aside from Go himself and whatever maladjusted Roidmude thought laundry made a fun game.

“Nothing.” Freeze was with Heart, a rarity in and of itself. Go tucked himself further into the corner, where he could better hear due to the vagaries of the building’s inexplicable use of central heat. “He resists reprogramming; his algorithms would destabilize, if I proceeded further, and the risk of data loss is intolerably high. Furthermore, he would be useless as leverage.”

“There’s no other way?” Heart sounded disappointed, and Go wondered why Brain wasn’t the one trying to extract information from whatever poor bastard was the current point of discussion.

“We have one option, if you wish him to remain functional,” Freeze said.“And given the current situation with 099, we cannot afford to lose him as a weapon. Not if we’re going to fight a war on two fronts.”

“099 is not your concern.” Heart sounded weary, as though he’d had this argument more times than he could count. Go kept still; although it sounded as though both Roidmudes had stopped right outside the little corner of the basement in which Go was hiding, Go was fairly sure he was farther away. He couldn’t tell where, though, and now he was curious despite the pounding in his head. “That option is not on the table,” Heart added. “I don’t trust him.”

“It’s not as though it were alive, in the traditional sense,” Freeze said, with an emphasis on the pronoun.

“We’re not alive in the traditional sense,” Heart reminded him. “He could be playing some sort of game, for all we know. He hated us while he was alive. I don’t see why he would hate us any less now that he’s dead.

Go frowned. _He?_

“It’s been invaluable in creating the core programming for Sigma Circular,” Freeze said, with a studied tone of nonchalance, followed shortly by the sound of a brief scuffle.

“You weren’t supposed to let him anywhere near –“ Go could almost hear Heart’s teeth click together. “He wasn’t to have access to the Sigma Circular project,” Heart said, and if Go hadn’t known him so well, he would have believed Heart was calm.

“As I said.” Freeze’s voice was silky, and Go could all but see the smug expression on his face. He wanted to punch it, but he was hiding and Freeze was still talking. “Invaluable. As you recall, it was by following his suggestion that Brain achieved his Ultimate Evolution.”

“Irrelevant. I won’t have him corrupted,” Heart said, voice clipped. “The answer is no.”

“Would you rather Mashin Chaser be reduced to a useless pile of junk?”

Whatever Heart might have said in response was lost under the roar in Go’s ears. Static washed through his brain, tilting him sideways against the wall. It cleared, leaving him with one palm flat on the ground and his heart in his throat, and he had no idea why. _Mashin Chaser._ He was supposed to defeat the Roidmude traitor who had allied himself with Drive and the rest of humanity, not accidentally overhear that their enemy was being tortured in the basement.

 _Why did you leap to the assumption that he was being tortured_ , Go asked himself, but he was convinced that whatever Freeze was trying to do wasn’t in Chase’s best interest. _Of course it isn’t_ , he thought fiercely. _He’s a traitor and deserves whatev-_ he couldn’t finish the sentence. It fizzled out, and it was just making his headache worse. _I have to go find him._ Go nodded to himself; that would solve his problems – he would simply look at Chase, and it would remind him of why Chase was the enemy and should be eliminated quickly and with mercy.

The maze-like layout of the basement meant that Go wasn’t sure what parts of it he hadn’t explored yet, but he thought he had an idea of where Freeze and Heart had been. The acoustics didn’t lie, even though they were twisty and sometimes unexpected. He poked his head out from around the machine and then stood slowly. Neither Heart nor Freeze was immediately visible. Go sauntered around the corner, trying to look as though he were bored and exploring.

“What’s the worst they would do,” he muttered. There was no good reason for him avoid looking around, no good reason he shouldn’t be able to see whatever was going on, when everyone in the building was on the same side. He couldn’t shake the wariness, no matter how many times he tried to tell himself that it was unwarranted.

The area most likely to echo through the vents so clearly was empty, when Go wandered into it, and he’d been in that particular cubby before. There were some old cleaning supplies leaning drunkenly against a wall, the mop dusty and dried into an unpleasant stiffness. Go frowned at it; the strings were bent at an odd angle, as if the mop had been jammed up against the wall in a new position.

“So you were in here.” He looked around, and finally noticed that one corner wasn’t flush with the wall. The standing partition hid a second exit from the room. Go stared at the empty canisters with their blurred kanji as if trying to kill time and listened carefully, but he heard nothing. “Here goes.”

The second exit led to a corridor running what had to be the width of the building, and the lack of space Go had noticed before resolved itself. The basement layout was less maze-like than he’d thought, once he stopped trying to account for the space that had been hidden. The lights overhead flickered, and Go put his hands in his pockets. There were a few doors, all on the left side of the corridor, and he nodded to himself, completing his mental map. None of them looked as though they had been opened, until he reached the end of the corridor and the last door.

Light was visible at the threshold, bright fluorescent white instead of the dim yellow in the corridor. Go listened again, but there were no sounds coming from the other side of this door, either. It was slightly ajar, opening outwards, and there was a heavy bolt on the outside. _Meant to keep someone in?_ The bolt looked newer than the rest of the door, but it was still an oddity. Go reached for the handle and hesitated. _You’ve come this far_ , he told himself, and pulled the door open.

The room was smaller than he expected, nearly empty shelves on the walls. The harsh lighting cast dark shadows, the faint whine of the elongated bulbs setting Go’s teeth on edge even before he gathered up the courage to look at the figure strapped onto the table in the center of the room. Chase still wore the purple leather, almost incongruously, tight pants in the same shade and heavy boots still on his feet. He was looking away from the door, but at the sound of Go’s footsteps he glanced back.

“You shouldn’t be here,” he said, and the sound of his voice sent a shiver along Go’s spine before the meaning of the words registered.

“Neither should you,” Go said. The cuffs holding Chase down were heavy and metallic, but they were held in place with simple mechanical pins. Go slid the first one free without thinking about it, opening the cuff, and Chase grabbed his wrist. _He’s the enemy_ rang in Go’s ears, Freeze’s human voice so clear that he thought the Roidmude had entered the room. There was no one else there. Go shuddered under the onslaught of inaudible sound, and Chase didn’t let go.

“Go,” Chase was saying, and some of the cacophony faded.

“You’re –“ Go said, and words failed him. Crawling fire behind his ear and he wrenched his hand out of Chase’s grip to brush off whatever was touching him, but there was nothing there. His fingers came away damp and red and he stared at them in confusion. Chase turned his head roughly to the side, peering at his skin, and Go wasn’t sure when he’d stood or when he’d freed his other limbs.

“001,” Chase said.

“What about him?” Go reached for the wound again, but Chase pulled his hand down.

“He’s altered your memory,” Chase said, and Go shook his head.

“He wouldn’t,” he said, but every misgiving he’d had over the past few days was crowding into his mind. Every time he’d caught Brain or Medic watching him with a speculative expression, every time some tiny detail didn’t quite add up, every time it seemed as though he’d had to carve out a new space in the Roidmude headquarters; all of it fit together in a way that made Go sick to his stomach. “They rescued me,” he said, but he couldn’t make himself believe it. “After Drive tried to – to….”

“Tomari Shinnosuke was searching for you,” Chase said.

“He wants to kill me,” Go retorted, but the words were wrong. “Why else would my sister have tried to have me arrested? Why else is there a warrant out for Mach?”

“Freeze is lying to you.” Chase stood, wavering slightly and then catching himself. A bruise was visible across the side of his face, and Go suddenly saw a vision of Chase under a bridge with a similar mark. It melted into the image of Chase on Go’s living room floor, in the apartment Go had almost forgotten he’d had, with Mad Doctor slotted into the Break Gunner.

“You – you were in my home,” Go said. Why would he have helped Chase, when Chase was a traitor and slated for execution?

“You saved my life.” Chase was answering the question Go hadn’t asked. “You did not tell me why.”

 _Why is Freeze holding him here, instead of killing him quickly?_ The counterpoint came quickly, persistent over Go’s half-hearted attempt to convince himself that Freeze and Heart must have had a reason to hold Chase prisoner. The conversation Go had overheard and already half forgotten rushed back. “They’re going to destroy you,” he said, and traitor or no, the thought of it opened a pit in his stomach.

“Yes,” Chase said, and for a moment Go would have believed Chase felt almost infinite sorrow before he straightened his shoulders again. “I will no longer support their cause.”

“Why?” Go burst out. “Why can’t Roidmudes and humans coexist?” Heart would forgive Chase, if he repented and returned, Go was sure of it.

“Shijima Go. Heart and Freeze have lied to you. I have told you this before.” Chase glanced behind him, at the still half-open door. “We are out of time.”

The only exit from the corridor was at the other end, where Go had slipped through a hidden passageway. Two Roidmudes stood between him and it, as he stepped uncertainly into the hall. Heart’s face fell, disappointment writ large, and 001’s human face rippled slightly as though he meant to transform into his Roidmude body and then thought better of it at the last moment. Chase stood just behind Go’s shoulder, Mach Driver securely belted around his waist. Go held his own Driver in his hand, uncertain.

“You should not have come here again,” Heart said.

“I won’t let you kill him.” The Driver settled against his hips, and Go held up his Signal Bike, and Heart’s choice of words pinged against his memory. “What do you mean, again?”

“He may be more trouble than he’s worth,” 001 said. “The amount of time it takes for my powers to fade does not correlate to any measurable parameter. There is no useful information here.” He glanced at Go as he spoke, and the stirrings of misgiving Go had felt sprung fully to life.

“Are you talking about me?” he asked, although he knew the answer. _Freeze stole my memories._

“You said you wouldn’t harm him,” Chase said. Go had thought he couldn’t be further shocked, but Chase’s quiet statement dropped the ground out from under his feet.

“What are you –“ he started, but Freeze wasn’t paying attention to him at all.

“His continued good health was contingent on your cooperation,” Freeze said. “Which has been lacking.”

Nothing he knew was true. Nothing he remembered was real. There was no way for Go to know what to do or who to trust, no way sort out the overload of information and vast howling blank spaces spinning around each other. The vortex howled in his ears, drowning out the conversation in front of him, and Go slammed the Signal Bike into the Mach Driver. He spit out his catchphrase, a faint sense of satisfaction blossoming at the surprise on Heart’s face and the annoyance on 001’s.

“If you had let me use the Banno program, this wouldn’t have happened,” 001 said conversationally, and pulled a tablet out of his pocket.

Heart rounded on him with real fury. “I told you that was not an option,” he said, and reached for the tablet.

“Your PTSD does not override the most sensible course of action,” Freeze snapped, holding the tablet out of reach.

“My word is final,” Heart said, and his form rippled and stretched into the shape of his Evolved State. Freeze followed suit, the only stable part of him the tablet still in his hand, and Heart struck at the tablet almost before Freeze’s outline solidified. Freeze ducked backwards, more graceful in his transformed state, and Heart missed.

A rough grip circled Go’s wrist. “Time to go,” Chase muttered, but there was no way they could get around the two struggling Roidmude leaders without being seen.

“We just need a head start,” Go said. His memories were full of holes and lies and he had no way of figuring out what the truth was, but he found himself willing to trust Chase. “All we need is to stall them for a second.”

Tomarle wouldn’t hold either of the Evolved Roidmudes for long, but the reprieve would get them down the hallway at the very least, and then they’d have a fighting chance. Go slid it into his Mach Driver and hoped desperately for success. The Signal Bike’s chime rang out and the corridor abruptly stilled, Heart’s face twisting into fury as he shuddered against the field holding him in place.

“Go, go, go!” The tablet was still in Freeze’s hand, and Go wrenched it free as he and Chase darted past. The crackling of the field breaking echoed through the corridors just as they cleared the doorway. “Faster!”

A bolt of energy shot past him and Go kept running, catching glimpses of Chase’s shimmering armor to the side. The blast struck the wall instead, hitting a support beam, and the ceiling above their heads started to crack. Go bit his tongue and grabbed Chase’s wrist with his free hand, pulling him quicker than Chase was apparently willing to run. The basement’s nearest exit was reachable by a set of stairs, shuddering as the ceiling started to fall.

“We can make it!” Go cleared most of the steps in a single leap with Chase in tow. Plaster dust rained down as he smashed through the door and a second energy blast from behind vaporized half the door frame. He kept going.

“You’re going to destroy the tablet,” Go heard Freeze shout, but the tablet was intact in his hand and they were nearly out of the building.

Blue sky and sunlight shone overhead, the pavement incongruously wet beneath Go’s boots. If they could reach his bike, they might have a chance to escape, or at the very least, reach a battleground that would give them a fighting shot. The bike was on the other side of the building, though, and the windows were lined with Roidmudes watching their leaders hunt him down. There was no way through. Go turned away from the building, pounding down the streets in a futile effort to get away. Dimly, he heard Heart snap at the massed Roidmudes to stay behind.

“We can’t run,” Chase said, almost in an undertone. Go released his wrist, turning to face their pursuers. Chase stood between them and him in a defensive stance, and Go started to shove him aside. He didn’t need protecting. Before he could do more than take half a step forward, the tablet hummed in his other hand, vibrating against his fingertips.

“I can assist you,” it said, and Go looked down. A stylized face flickered to life, a shape consisting of nothing more than pixels on the screen, and yet there was a hungry edge to it. It stared into Go’s eyes as though Mach’s visor didn’t exist, image shifting slightly. It felt as though the tablet were trembling in anticipation.

“How?” Go asked. Heart and Freeze stood outside the door, no longer running now that their prey had stopped, and the peculiar sensation of a Heavy Acceleration Field shivered through the air. The shadows around them slowed, the wind caught in fits and starts, but it washed over his armor and left him unaffected. The tablet was caught in his protective influence, still active in his hands.

“My mind, fused with your body through the Mach Driver,” the face said. “I can reach the limits of what the Driver is capable of.”

“What are you?” Go asked, and then a more important question occurred to him. “ _Who_ are you?” The name _Banno_ echoed, Heart and Freeze arguing. “Are you really my father?”

“We don’t have time for this!”

There was a familiar cadence to the snapped phrase, an echo of memory long lost that evoked a cascade of guilt. Go shook his head. “No,” he said, but the tablet shook harder. Its edges split apart, cables snaking out, and Go tried to drop it. One of the cables wrapped around his wrist, and he tore it free. Another slithered up his other hand and yet another insinuated itself into the Driver, and he couldn’t stop them.

“Go?” Chase glanced over his shoulder, and a flash of motion was all that registered at the edge of Go’s vision before Heart sped toward them on the left and Freeze stalked in his wake. Heart slammed into Chase, knocking him aside, and Chase went sprawling. Heart followed, one glistening fist raised, and Go couldn’t pull the writhing cables free to help his ally.

The tablet had fully broken apart, its bits and pieces snaking around Go’s limbs as it wormed its way into his Driver. The armor disintegrated around him, and time slowed. He was heavy and motionless, Chase and the two Roidmude leaders nothing more than blurs moving too quickly for him to track. He heard the fireball before he saw it, stuttering orange and yellow blossoming toward him. He couldn’t move to avoid it, only watch it coming, and then something yanked him away.

The ground rose up to meet him, limbs useless in warding it off, and filled his vision. He could see every crack in the pavement, knowing he was going to hit it long before the first scrape of concrete against his elbow dragged his arm down and behind him. A wash of heat from the direction of the battlefield struck him at the same moment time snapped back into its proper flow and he skidded along the ground. Go came to a halt on his back, dizzy and shaken, ears ringing with sound he hadn’t quite parsed. Smoke poured into the sky overhead, jarring him out of his half-daze.

“Chase!” Go scrambled to his feet, wincing at the bright shock of pain along one arm, and swung around toward where he thought Chase had been fighting. He expected to see Heart and Freeze standing over a flutter of ash and the few broken remnants of Chase’s Core, but none of the shapes standing in front of him looked they way they should. Go blinked, finally recognizing Chaser’s shimmering armor standing next to a bright red figure. The newcomer’s armor was an unfamiliar configuration, but its base looked like Drive. “Shin?”

Chaser’s suit fell away, melting into the familiar jacket and pants. He looked a little worse for the wear, but he had survived mostly intact. Relief prickled along Go’s skin, and then he remembered that Drive had tried to kill him. Drive was his enemy. _Heart and Freeze just tried to murder you, too_ , it occurred to him, and he didn’t know what to believe.

The red armor vanished, pieces spinning out and fading into nothing, and Shin stood facing Go with a wary expression. Go backed up a step; Shin wasn’t the one who should be feeling nervous, he thought, and the belt around his waist suddenly tightened. The Driver was still attached to him, he realized, and the belt was digging into his skin. It was painful, and he pulled at the sides. It should have released, when the transformation faded, but it kept squeezing.

“You can’t run away from me this time.” The voice came from everywhere and nowhere, pouring through his ears and sliding into his brain. Go spun around, searching for the speaker, but the only people he could see were Shin and Chase.

“Where are you?” he demanded.

“Go,” Shin started to say, but he wasn’t important.

The belt had sunk itself into Go’s skin, plunging tiny hooks into him, and he couldn’t pull them out. His fingers were slippery, skidding along the belt’s surface as he tried to tug it free, and it wouldn’t come loose. Go felt scratching along the edge of his thoughts, a foreign presence trying to worm its way inside him, and the parts of him it touched started to crumble. His heart rose into his throat, beating frantically against his breath rasping in his ears as he tried to stem the rising tide of panic.

“This won’t do,” said the voice, coming from the inside of Go’s head. He couldn’t get it out. “No,” the voice continued. “You will be silent.”

The world around him vanished.

**Notes for the Chapter:**

> Posting schedule is shifting to every 2 weeks. I'm 85% sure I can maintain that schedule. (This was supposed to be a fun little thought exercise and now I appear to be re-writing the second half of the show. Yay.) See you on the 8th~


	7. Chaos and Fractals

“No, really, it’s fine.” Go’s smile was tight around the edges, his eyes shadowed. Shinnosuke watched Kiriko hover around her brother, unable to accept that he looked and acted mostly fine despite having been missing for well over a month.

“I was worried,” Kiriko said, biting her lip.

Go looked around the Drive Pit, sitting with his legs pressed close together and his hands set rigidly over his knees, as if trying to take up the least amount of space possible. Shinnosuke was starting to see why Kiriko was worried. “I’m fine,” he said, but if his grimace was an attempt at a reassuring smile, he’d missed it by a mile.

“You should at least let someone look at you,” Kiriko said. “You were – you were with them for six weeks.”

“No,” Go said, almost before she’d finished talking, with an edge of panic to his voice. “I don’t need to be examined.”

“Okay,” Kiriko said, backing off. “Okay.” She looked him up and down, but Go didn’t look injured. Hadn’t, Shinnosuke remembered, even after the belt had fractured around him and he’d been stuck in the Heavy Acceleration Field. Shinnosuke had had no faith in his hastily cobbled-together plan of _distract Heart while the rest of the team clears the field_ , but Heart had played into it perfectly. Given that the fight had ended with Heart in an entirely new body and laughing at Shinnosuke with a quietly murmured _Well played, Kamen Rider Drive_ , he still wasn’t convinced his plan had actually succeeded.

Shinnosuke glanced over to the other side of the room, where Rinna was muttering over the disintegrated Mach Driver. Go hadn’t been able to answer satisfactorily when asked why it had failed so spectacularly, only shaken his head and repeated that he didn’t know. He hadn’t been able to account for the entire time he’d been missing, either, hadn’t remembered the few times Shinnosuke had seen him fighting with the Roidmudes.

“001 really did a number on him,” Shinnosuke said to Chase. The Roidmude was something of a captive audience, still suffering the aftereffects of his own confinement and experimentation, and not entirely present in the conversation. Mad Doctor had repaired what he could, for the most part, and it didn’t look as though Chase’s programming had been subverted. As far as Shinnosuke could tell.

“There’s only one of me,” Rinna had said sharply, holding up the remnants of the Mach Driver, when Shinnosuke had wanted to know if she could evaluate Chase for hidden traps. “Let Kyu keep looking.”

“Freeze is dangerous,” Chase said slowly. He was hooked into a cobbled-together diagnostic framework; it was the same rig Rinna had been using to analyze the piece of 050 in order to separate humans fused with Roidmudes via the Neo Viral Cores, and it was currently feeding Chase enough power to effect repairs on his damaged systems. “Heart’s new form makes him more dangerous.”

“Yeah, buddy.” Shinnosuke patted Chase’s hand, smiling a little at the indignant look Chase gave him a full six seconds too late.

“Quiet,” Kyu said. “This is harder when he’s talking.”

“Okay, okay.” Shinnosuke went to go offer moral support to Kiriko instead, but she had vanished with Go while he wasn’t paying attention. He wandered over to Rinna.

“It’s completely trashed,” Rinna said. “There’s something else in here, and I don’t know what it is. Are you sure Go doesn’t know anything?”

“That’s what he kept telling Kiriko,” Shinnosuke said. “But they’ve both left.”

Rinna’s mouth twisted for a moment, and Shinnosuke made a mental wager as to whether or not she would actually curse. He lost; her face smoothed out again and she sighed. “I’m going to conduct an analysis, but don’t expect much,” she said. “Whatever it was integrated itself into the Driver and then.” She gestured with one hand. “Poof. It looks like it self-destructed.” She paused. “Or the Mach Driver killed it, but I don’t think it has that capability. It’s not built for it.”

“If anyone would know, it would be you,” Shinnosuke told her.

“If Professor Harley would answer messages, I might have more insight,” Rinna said.

“You built another Driver,” Shinnosuke pointed out.

“Tomari.” Rinna turned to face him. “Just because I made a perfectly working copy doesn’t mean I have insight into all of the complexities and nuances of the system.”

Shinnosuke sighed. “I’ll leave you to it,” he said, lilting the end of the sentence up just enough for it to be taken as a question, if RInna chose to interpret it that way.

“Yes, yes,” Rinna said, already focused on the mess that had been a working Driver at one point.

Shinnosuke left the Drive Pit; he felt at loose ends, no clear task to accomplish despite the rest of his team either busy or in recovery, and he hated not having a purpose. _No, you don’t_ , he thought, trying to convince himself that he welcomed the chance to slack off, but it was different when there were issues to be addressed and he couldn’t make headway on any of them. Even Krim was still in the Drive Pit, assisting Kyu.

The sun had set, while Shinnosuke had been underground, and he was surprised at how late it had gotten. The sky overhead was dark, stars invisible through the glare of the city lights, and Shinnosuke started to walk. With Tridoron parked in the center of the Drive Pit, he was stuck. Shinnosuke smiled briefly; he could have borrowed one of the vehicles from the driving school, but that was something he thought Go might have done, and not the appropriate course of behavior for a law-abiding citizen. Particularly not one who needed to retain the goodwill of the hosting organization hiding his secret superhero base.

_Can I help?_ He sent the text to Kiriko without hesitating too much, sliding the phone back in his pocket before he could stare at it to see if she’d read it, or until she replied. The bus station wasn’t far.

The Ride Macher sliding around him and idling to a stop half a meter away nearly startled Shinnosuke out of his skin. A sticky note was taped to it, in Kyu’s handwriting; Krim had thought he might like to not navigate public transportation. “And if Go doesn’t have a passenger helmet stashed in here, then back you go,” he said to it, but there was a perfectly viable helmet. Shinnosuke’s pocket buzzed, just as he swung a leg over the bike.

_No, I’m taking him home_ , read Kiriko’s text. _We’ll see you tomorrow._

“Of course you will,” Shinnosuke said, sending a quick acknowledgement. It did nothing to curb his restlessness. He started the bike, remembering too late that Go had modified the engine just enough to give it a dramatic rumble without quite landing outside the bounds of legality. Despite the kind gesture, Shinnosuke suddenly didn’t want to drive Go’s bike all the way home and then back again. Go didn’t live far from the driving school, he remembered, and he did live relatively close to a train station.

It took a few tries for Shinnosuke to find Go’s building; he’d thought he remembered exactly where it was, but the tiny broadcast tower on the opposite corner wasn’t illuminated after dark and he ended up finding the temple across the street first. “Cheapskates,” Shinnosuke muttered at the NTT logo sitting in shadow on the tower that he could only see against the dim sky now that he knew it was there.

There was designated motorcycle parking under the building, each slot numbered and all of them empty. Shinnosuke hesitated for a moment and then parked the Ride Macher on the end. Go could move it, if he needed to. He bounced the key on his palm and jogged up the stairs. He didn’t make it to the center of the outdoor corridor before Go’s door opened and Kiriko stepped out. She stopped when she saw him, and then closed the door quietly.

“Hey,” Shinnosuke said, and Kiriko walked halfway across the distance between them before she answered.

“He’s asleep,” she said. “What’s going on?”

Shinnosuke held up the bike key in answer. “Krim thought I might not want to take the train home,” he said. “Since I left Tridoron in the Drive Pit.”

“That was thoughtful of him,” Kiriko said absently. She pocketed the key and kept walking. Shinnosuke looked at Go’s closed door and then at Kiriko’s retreating form.

“Um,” he said.

“I’ll give it to him in the morning.” Kiriko was giving him the look that said she wasn’t about to be dissuaded, and Shinnosuke let it go. “Do you want a ride?” she asked.

“Uh, sure.” Shinnosuke hadn’t noticed the van Kiriko tended to borrow when she wanted to drive, but it was in the lot below the building when he followed her to the opposite corner from where he’d parked. He got into the passenger seat, buckling his seatbelt and waiting for Kiriko to talk if she wanted to. It didn’t take long.

“I’m worried,” she said, glancing at the mirrors before driving through a blind intersection. “He doesn’t seem right.”

“001 had him for a while,” Shinnosuke said.

“Exactly.” Kiriko glanced sideways. “The scar behind his ear is still fresh.”

“The snowflake?” Shinnosuke couldn’t help looking at Kiriko. There was a matching scar behind her right ear, hidden now by the lack of illumination in the van, but if he looked at it in daylight he knew he would see faint pink lines of healed tissue.

“001 altered his memory more than once,” Kiriko said. “And I don’t know if we should leave him alone.”

Shinnosuke did not point out that Go was currently alone in his apartment, and the two of them were driving away from it. “You weren’t affected by the memory alteration,” he said.

“But he was.” Kiriko’s shoulders were rigid, arms stiff as she took the van through another turn, and Shinnosuke almost expected the van to scrape against the cinderblock wall at the corner of the narrow street.

“The antidote,” Shinnosuke said.

“Chase took it with him,” Kiriko interrupted. “But that was weeks ago, and if he gave it to Go then, why didn’t they come back earlier?”

“I meant that giving it to him now might help him remember the last six weeks,” Shinnosuke said.

“Maybe.” Kiriko bit her lip. The van reached a main street, and she pulled onto it with more relaxed movements. “Maybe I’m just being paranoid.”

“Heart and Freeze wouldn’t have been chasing them so hard if they hadn’t been trying to run,” Shinnosuke said. “This isn’t some sort of – Manchurian Candidate situation here.”

“Manchurian what?” Kiriko looked at him again, long enough that Shinnosuke was worried about how much attention she wasn’t giving the road.

“It’s a movie,” he said, and she rolled her eyes before returning her gaze to the street ahead of them. “About –“

“I can guess,” she said tartly. “That wasn’t what I meant.”

“Go’s always fine,” Shinnosuke said, trying to be reassuring. “He’s gotten back up every time.”

“He’s been through a lot,” Kiriko said. “I mean, I know we all have, but.”

“He’s your little brother,” Shinnosuke said. “I get it.” He smiled at her, and got a genuine smile in reply. Kiriko seemed a little reassured, when they reached Shinnosuke’s building, and he squeezed her shoulder without thinking before climbing out of the van. She blushed, and he opened his mouth to apologize. No words would come out, and he felt his own face growing warm. “Uh,” he said, and scrambled to escape and close the door.

Kiriko drove off without so much as looking at him again, eyes fixed straight ahead, and Shinnosuke glared at his hand.

“You traitor,” he said to it, but it just sat there innocently, as if it hadn’t started exposing the crush he’d had on his coworker and partner for months. Shinnosuke used it to slap his face lightly. “You have more things to worry about,” he said out loud, and one of his neighbors opened the lobby door just as Shinnosuke started talking. “It’s nothing,” Shinnosuke said to the man, but his neighbor only walked away faster.

_One day_ , Shinnosuke thought, making sure to keep the words purely internal, _I will not stumble into any ridiculous pitfalls of perfectly normal social interaction._ It was also possible that his internal voice was laughing at him. Shinnosuke decided to ignore it. _Tomorrow is a brand new day. We’ll work everything out._

* * *

Kiriko stared at her brother across his table, tucked into the corner of his kitchen and covered in disorganized papers. It wasn’t his usual type of disorganization; there was actual dust around the edges, and it looked more like he’d just thrown more and more onto the top of the already precarious stack without sorting through anything. _He hasn’t been here_ , she reminded herself. _Of course it’s dusty._ It was his second morning back at home, though, and Kiriko wouldn’t have expected him to ignore his environment so thoroughly.

“What?” Go said, without a trace of self-consciousness. He was drinking his coffee black, Kiriko noticed, but it wasn’t as though the milk that had been in the kitchen when he’d disappeared would still have been good. Kiriko had thrown it out, after the first three weeks, along with everything else perishable, and kept paying his rent. It hadn’t been easy.

“It’s going to take Rinna a while to fix the Driver,” she said. She’d declined his offer of coffee, but there was still a water glass in front of her. Kiriko couldn’t help but be annoyed that he hadn’t just left it alone, when she’d said no, as if she cared whether or not he was a polite host.

“Okay?” Go was sitting up entirely straight, that was it. That was the other part of the picture that was bothering Kiriko. He tended to sprawl, when sitting still, and Go didn’t do that often. Kiriko set the thought aside and focused on the fact that her brother was apparently being deliberately obtuse.

“Stay away from the Roidmudes,” she said bluntly. “Tomari and Chase can manage anything that comes up until you can use the suit again.”

Go frowned, corners of his mouth turning down unpleasantly, and he looked at his half-empty mug. “I can do that,” he said. “If you think it’s really important.”

“Yes,” Kiriko said, without missing a beat. She’d been prepared for an argument, and not getting into one took the metaphorical wind out of her sails. “It’s absolutely important.”

Go fiddled with the mug for a moment before raising his eyes to meet hers. “I wouldn’t want to do anything that made you sad,” he said.

“I know,” Kiriko said. “Just. Please stay away from – everything, until we can fix the Driver.”

“I’ll be waiting,” Go said, and there was an easy flow to the words that set Kiriko’s teeth on edge. She knew what that tone had meant, when Go was younger.

“I mean it,” Kiriko said sharply, and Go had the grace to look abashed.

“Okay, okay, I won’t go looking for a fight, are you happy?” he said, and he sounded more like himself.

“Yes.” Kiriko raised her glass to sip at the water and caught sight of the time. “I’m late. Dammit.” She grabbed her jacket off the back of the chair. “You promised,” she added.

“I know, I know.” Go waved at her, standing almost formally and following her to the door. “Go and return safely.”

“Let me know if you leave,” Kiriko said, because of course she was going to check in on her brother again at the end of the day and he knew it.

“Yeah, yeah.” Go closed the door behind her. He still hadn’t fixed the hole in the mailbox, Kiriko saw, and then she had to run down the stairs to make it on time.

“We’re heading out,” Tomari said as soon as Kiriko cleared the door. She glanced at Honganji questioningly, and he nodded.

“Officer Tomari will give you the details on the way,” he said, and Kiriko followed her partner to Tridoron.

“Well?” she said, as soon as they had wheels on the road.

“Might be a Roidmude,” Tomari said, and explained that a woman had vanished. “Right in front of her husband,” he added, and it was the second case in two days in which the woman had disappeared while clearly out with her husband or partner.

“Literally vanished,” Kiriko repeated.

“Poof,” Tomari confirmed. “We didn’t get to the first scene, because those rat bastards in the First Division decided that the boyfriend was day drinking and hallucinating.” He paused. “His BAC wasn’t zero, but still.”

“And the second?” Kiriko prompted.

“Married couple, no kids, supposed to leave on a trip this afternoon. Something about getting a head start on re-creating photographs, so they were in a scenic park.” Tomari hesitated. “They were, um. Affectionate.”

“Ah.” Kiriko felt herself blush, and looked resolutely out the window in the other direction. “Did they see the Roidmude?”

A rustling noise sounded, and then Tomari answered. “Ah, no. But they were pretty distracted. And then she disappeared.”

“Right.” The blocked-off scene was particularly beautiful, surrounded by hedges of azaleas in bloom. Kiriko glared at the bright shades of pink and checked for the residue of a Heavy Acceleration Field while Tomari spoke to the left-behind husband.

“It’s a Roidmude,” she confirmed, when Tomari finished his interview and jogged over to her again. “But if he didn’t see it, we don’t have much to go on.”

“And we don’t exactly have enough similarities to build a pattern,” Tomari said.

“There’s the obvious,” Kiriko pointed out. “Both of them were on what you could describe as a date.”

“Still.” Tomari chewed at his bottom lip. “Let’s see if there are any connections between the victims.”

The only possible connection that Kiriko could find turned up early; the two women had been similarly dressed when they’d disappeared, and they both had long, undyed hair. It still wasn’t enough for a pattern, not with only two data points. Kiriko glared at the printouts comparing the victims and their partners. “They wouldn’t have gone back to where we found Go and Chase.”

“Heart’s moved on by now,” Tomari said. “I sent Shift Cars to check.”

Kiriko sighed, propping her chin on her hand. “There has to be something we can do besides just wait for the Roidmude to strike again.”

“Like set up a decoy?” Tomari asked absently.

“Um.” Kiriko herself would be close enough to the appearance of the two current victims to act as bait, if she put on the right clothes. “I guess?” she said. Both of the disappearances had been relatively close together; if they lurked in the general vicinity between the two locations, it wasn’t a bad plan. Tomari was the natural choice for the other half of the decoy, and Kiriko could almost look forward to -

“Tomari Shinnosuke. Shijima Kiriko.”

Chase’s voice startled Kiriko, her cheeks burning at being caught having improper thoughts about her partner, and she flinched hard enough to knock the reports off the desk. Tomari’s ears were pink, when she glanced guiltily at him. “Chase,” she said faintly.

“I require your assistance,” Chase said. He turned and left the SIU office without another word, and Kiriko scrambled to dump the disordered papers back on the desk before following. Tomari crouched down to help, and knocked her forehead with his as he reached for the sheet of paper farthest under the desk just as she tried to pick it up.

“Ow,” Kiriko said, and Tomari’s hand was just brushing against hers. She leaned toward him, and then blinked as she remembered why they were on the floor in the first place. “Chase,” she said, and Tomari looked upset for a brief moment before dropping the files on the desk.

“I really wish he’d stop doing that,” Tomari said, and followed Kiriko out the door.

Chase was out of sight by the time they cleared the office, but Kiriko made a guess that he was headed for the Drive Pit. She was right; he was standing dramatically in the center of the empty floor when she got there, Tomari on her heels, and Go was sitting sulkily on the catwalk above him. It was eerily similar to the pose he’d adopted when he’d been confined in the Drive Pit after the incident with 007.

“What’s going on?” Kiriko asked. Krim was on his mobile stand, just below where Go was perched. He was between Go and Chase, it occurred to her, and she wasn’t sure who he was trying to protect. _Why would one of them threaten the other_ , she told herself.

“Go has been targeted,” Chase said, and Kiriko lost her train of thought. “By 006. He has partnered with a human and achieved an evolved form.”

“Why?” Tomari asked. All traces of awkwardness were gone; he stepped into the room around Kiriko, looking calmly up at Go.

“I don’t know,” Go said.

“Banno Tenjuro,” Chase said suddenly, and Go looked up as if in answer, flinching hard at the name.

“What?” Tomari said, looking between Go and Chase.

“I believe 006 has been instructed to retrieve Banno Tenjuro.” Chase lifted his chin a little.

“Wait, what?” Tomari lost some of his poise at that, switching his attention to Chase. Kiriko kept watching her brother; he’d gone still and wary, and he looked almost predatory despite not having moved a muscle.

“Go removed the device containing Banno’s consciousness when we fled,” Chase said. “He denies that he has it now.”

“It broke,” Go said. “While we were running.”

“When you say Banno’s consciousness,” Tomari said carefully. “You’re talking about Mr. Belt’s partner.”

“He’s not my partner,” Krim interjected. “He was a madman, and the fact that he placed his consciousness into a tablet only shows that he stole my work.”

“That’s not the point,” Tomari said. “Where is he now?”

“Gone,” Go said forcefully. “I told you, the tablet broke while we were running.”

“Why didn’t you say something?” Tomari asked. “Losing your father -” He broke off, teeth clicking together audibly as he clapped a hand over his mouth with a horrified expression.

“What?” Kiriko said sharply. Tomari had to have made a mistake; her father had disappeared a long time ago. He’d been some sort of research scientist, leaving his family behind to pursue his work instead, and although her mother had been careful not to malign her ex-husband, Kiriko had been able to read between the lines when she remembered those conversations as an adult. Puzzle pieces she hadn’t known were out of order fell into place. “He left us to create the Roidmudes,” she said.

“I’m sorry,” Tomari started to say.

“You _knew_?” Kiriko said to Go. “You knew, and you didn’t tell me?”

“I -” Go just looked at her, mouth slightly open.

“You knew that our father – _our father_ – created the Roidmudes, and you didn’t tell me. You hid Chase, and you didn’t tell me. You’ve been lying to me ever since you got back! The only thing you didn’t lie about was getting the Mach Driver from Professor Harley!” She rounded on Tomari, who had been in on the secret and hadn’t said a word to her either. “And you.”

Tomari, at least, had the grace to look abashed. “Go asked me not to tell you,” he said. “He wanted to get rid of the Roidmudes. Fix the problem Banno created. Before you had to know.”

“Well?” Kiriko turned back to her wayward brother. She caught the edge of an almost cold, calculating expression before he hastily rearranged his face to confusion and then something resembling sorrow. No trace of guilt or apology was visible, and Kiriko suppressed a sense of misgiving.

“I’m sorry,” Go offered, and Kiriko didn’t want an empty apology.

“Why didn’t you _trust_ me?” she asked.

“I...” The single word trailed off, Go staring at her blankly, as if the question itself made no sense.

“Never mind,” Kiriko said. She couldn’t manage Go’s feigned lack of understanding along with the Roidmude case, and only one of those was likely to result in a positive outcome. “Tomari, we should try to draw out the Roidmude.”

“Uh.” Tomari, despite standing head and shoulders taller, somehow managed to convey the impression that he was looking up at her, and Kiriko remembered she was upset with him, too. “Should we get -” he started.

“You and Rinna can act as one decoy,” Kiriko interrupted. Having their resident engineer as bait instead of rebuilding the broken Mach Driver wasn’t the best use of resources, but she didn’t want to be alone with Tomari. A deeper thought, quashed before it reached the surface, was that Go could very well suffer from the boredom and inactivity of waiting for his Driver to be rebuilt and Kiriko wouldn’t be sorry about it. He would be safe enough in the Drive Pit. “Chase and I can act as a second.”

“Chief Honganji wants Rinna partnered with Lt. Otta,” Shinnosuke said, staring at his phone. “You and I are playing decoy number two.”

“How does he already -” Kiriko clicked her teeth together.

“If 006 is chasing Go, looking for Banno, the best place for him to be is here,” Tomari said. “Chase can stay with him, in case of, um. Emergencies.”

“I don’t need a babysitter,” Go said. “I’m perfectly capable of -”

“Rinna has to rebuild the Mach Driver, remember?” Kiriko told him. “And she won’t be doing that while she’s trying to draw out a Roidmude.” From the expression on Go’s face, he’d completely forgotten about the Mach Driver, and Kiriko clamped her mouth closed over the further scolding she wanted to deliver.

“I believe this is the correct distribution of resources,” Chase said evenly, and Go threw up his hands dramatically.

“Fine, I’ll stay here, are you happy?”

“Extremely,” Kiriko bit out. “Tomari. Let’s go.”

* * *

The argument in the Drive Pit had been a sign, Shinnosuke decided. It had clearly indicated a failure to communicate, which was itself a clear prediction of the failure of the Roidmude to show up anywhere near either set of decoys. It had been days, and not only had two more women been kidnapped, the Special Investigation Unit had still seen neither hide nor hair of the Roidmude responsible. The only positive aspect was that the Roidmude hadn’t continued with its pattern of one woman per day; no, it had taken four victims over the course of a week and a half. It wasn’t much of a silver lining.

Kiriko not talking to him was the worst of it; not that she was ignoring him, Shinnosuke reflected, but she kept the conversation strictly professional, strictly in line with work. The one time she’d been open had been a request to leave her alone until she was ready. It wasn’t easy, but Shinnosuke gritted his teeth and set out to prove that he could respect boundaries and be trusted. So far, all it had gotten him was Kiriko’s continued professional partnership.

“Shinnosuke,” Mr. Belt said, interrupting Shinnosuke’s train of thought. They were parked at a scenic overlook for a few minutes, close to where other victims had been taken, and the sudden voice out of the silence made Shinnosuke jump in his seat.

“What,” he said, drying his suddenly moist palms on his pants.

“We know who it is.” That was Kyu’s voice, patched through the Drive System’s communications function. “Rinna and Genpachi got a good look at the Roidmude, and we know who it’s copied.”

“Well?” Shinnosuke prompted, when no further information was forthcoming.

The Roidmude had broken the door off of the borrowed car and nearly stolen Rinna before literally throwing her back at Otta; she was piqued at its apparent rejection, according to Kyu, but more importantly, the Roidmude had copied a well-known but reclusive fashion designer. Of Japanese descent, the designer was a foreign citizen who had been spending time in Tokyo in preparation for unveiling new lines of product.

“He’s apparently been missing for weeks,” Kyu said. “Or days. It’s hard to say, because he keeps to himself to much, but no one has been able to verify that they’ve seen him in person since at least late April.”

“Send someone -” Shinnosuke started.

“Already on it.” There was a rustling sound and Shinnosuke heard a keyboard tapping. “Officers are already checking his last known address and conducting interviews of his neighbors and known associates.”

“Check any facilities he’s rented or reserved,” Shinnosuke told him. “If the Roidmude copied him, it might be using one of those buildings.”

“Right,” Kyu said. “Got it.” He paused. “I’m checking online, too. Whatever information is out there, I’ll find it.”

“I know you will.” Shinnosuke closed the connection and started Tridoron; given a solid lead, he was better off actively investigating it. “Let’s head back.”

“Tomari,” Kiriko said, and Shinnosuke paused before shifting the car into gear. “When you learned that Banno was my father...” She trailed off, not meeting his eyes. “I’m not quite sure how to say this.”

“I should have told you,” Shinnosuke said, before she could continue. He’d had time to think about why she’d been upset, and he couldn’t in good conscience conclude that she was acting unreasonable. He didn’t think he’d been completely out of line, either, but he was willing to reconsider his own actions. “Go didn’t want you to have to know, and I wanted to protect you the same way.”

“Go is – he means well.” Kiriko gave a short laugh, but there was no humor in it. “He always tried so hard to be the adult, growing up.” She twisted her hands together, and hesitantly looked toward Shinnosuke. “That doesn’t mean -”

“I should have trusted you,” Shinnosuke said. He understood Go’s desire to protect his sister all too well, but wanting his partner to be safe didn’t mean keeping information from her; even if she wasn’t on the front lines with him, she was a vital part of his team. “You’re my partner, and I should have known that you could handle learning something difficult.”

“Thank you for seeing that,” Kiriko said. Some of the tension had drained out of her posture, and Shinnosuke felt himself relax a little in response. “We can’t work together if we don’t – work together.”

The sentence took a moment to parse properly, but Shinnosuke huffed out a brief chuckle. “You’re not wrong.”

“We have an investigation to conduct, Officer Tomari,” Kiriko said, but some of the easy warmth that had been missing was back in her voice.

“Yes, ma’am,” Shinnosuke said, throwing her a mock salute.

“Don’t push it,” Kiriko said, but Shinnosuke was fairly sure she wasn’t actually upset.

“Did you talk to Go?” he asked, pulling the car onto the street.

“Not yet.” Kiriko was biting her lip, he saw out of the corner of his eye. “Does he seem off, to you?”

“I don’t know him as well as you do,” Shinnosuke said, although he remembered Kiriko saying she didn’t think she knew Go as well as she had before he’d gone off to the States on a whim and come back with a vendetta and a set of superpowered armor.

“You know him well enough to tell me if he’s been acting different over the last week,” Kiriko said.

“Heart had him for a while,” Shinnosuke said. “And we don’t know what Freeze might have done.”

“It’s not just that.” Kiriko drummed her fingers against the door. “He wouldn’t take the antidote, but if he broke out of Freeze’s brainwashing, it might not matter.” She paused. “Did Chase say anything to you?”

“No.” Shinnosuke stopped at an intersection just before the light turned red, ignoring an annoyed honk from behind him. Speeding through intersections without good reason was how accidents happened. “He would have told us, though, if there was something we needed to know.”

“Sometimes I’m not so sure about that.” Kiriko glanced at the side mirror and then twisted around in her seat. “That’s Genpachi behind us.”

“Why wouldn’t he just call,” Shinnosuke muttered, and pulled Tridoron into the nearest parking lot.

“I found it.” Otta waved a book at them, his unmarked car parked haphazardly behind Tridoron, engine still running as he climbed out of the driver’s seat. “I think I know what the Roidmude is after.”

“What?” Shinnosuke fumbled with his seatbelt, trapped in the front seat for an embarrassing several seconds before he extracted himself. Kiriko was already looking at the book when Shinnosuke pulled his foot free from the wheel well and jogged over.

“Where did you find this?” she was asking.

“Used bookstore.” Otta smirked. “Kyu might be the god of the internet, but I know how to follow a lead.”

“What?” Shinnosuke repeated. “What did we learn?”

“Here.” The book was out of print, a limited run that had been published the year before as a promotional item in preparation for the designer’s sojourn to Japan. “This interview. Where he talks about the necklace.”

“So he wants to marry the woman who looks the best in his perfect necklace.” Shinnosuke emphasized the words with air quotes, ignoring Kiriko’s eyeroll. “In a church.”

“We’re already analyzing his movements to figure out what church he might pick,” Otta said.

“What about where he might be hiding?” Kiriko asked.

“Back to headquarters,” Shinnosuke said. “To put it all together.”

* * *

The address on the small plastic rectangle was incorrect. Chase frowned at it, aware that he was mirroring the expression in the photograph perfectly, and thought again about asking if he could get it changed. It would function as a form of identification as well as permitting him to legally operate the Ride Chaser and any personal four-wheeled vehicle in the correct weight class, and Chase wasn’t sure it was appropriate to have Go’s address listed. Given that he didn’t have an address of his own, he didn’t have a solution to the dilemma, either, no matter that Go had provided documents allowing him to get the driver’s license in the first place.

“Talk to Otta about a rush course,” he’d said, when Chase had figured out he was supposed to have permission to operate his own vehicle.

“Wouldn’t Tomari Shinnosuke be a more appropriate choice?” Chase had asked.

“You don’t want to bug him, do you?” Go had replied. “He’s busy trying to find the Roidmude.”

Chase hadn’t seen the logic of that particular statement, given how similar the tasks Lt. Otta and Tomari Shinnosuke had been assigned, but he’d been willing to give Go the benefit of the doubt. It was harder to allay his concern that leaving Go unattended would make him delinquent in his own task; he couldn’t protect Go from potential assault on the part of 006 if he was sitting in a driving class and Go wasn’t.

“I’ll stay here,” Go had said. “Won’t leave. The Drive Pit is perfectly safe.”

There was a particular human phrase for this, Chase was sure of it. “Do I have your word,” he said.

Somewhat to his surprise, Go had laughed. “Sure,” he’d answered easily. “My word. You can have it.”

It had left a bad taste in Chase’s mouth, but he had no reason _not_ to trust Go. He had an excellent reason not to be on the wrong side of human law, and Go was always in the Drive Pit when Chase returned to it to accompany him home at the end of the day. The first night, Go had looked at him and apparently assumed that Chase would be staying.

“How else are you supposed to keep an eye on me?” he’d asked. Chase thought the question had been distinctly derisive in tone, but he was also willing to accept that he wasn’t familiar with human emotion and the expression thereof. It was possible that this was part of a broken attempt at human courtship, but Go wouldn’t give him a straight answer to any of the hints Chase kept trying to leave, and no one he spoke to thought direct questions were a good idea.

Ergo, Chase was now compliant with human law regarding his motor vehicle, but still no less confused than before with respect to Go. He shoved the plastic rectangle into his pocket and jogged down the stairs to the Drive Pit. He’d failed to explain to Go that he would be taking the test that day and would therefore be able to spend more time actively carrying out his assigned tasks, but Chase didn’t anticipate any consequences for his minor lapse in memory. He touched his jacket over the small rectangle, feeling a small sense of accomplishment; the license was uniquely his, and it was a new experience.

The Drive Pit was full of voices, when Chase jogged down the stairs, audible through the closed door. None of them belonged to Go. Chase hesitated before entering, unaccountably nervous. No one noticed him at first; he had enough time to scan the room and ascertain that Go was not, in fact, present before Tomari beckoned him over. Otta was standing in front of a whiteboard with Kyu, both of them pointing at a map and arguing, and Rinna ignoring them both to place magnets with little dolls attached at several different locations. Honganji was nowhere to be seen.

“Go get lost on the way down here?” Tomari joked when Chase got close enough for conversational speech, and then the smile slid off his face as Chase couldn’t answer and Go didn’t walk into the room. “Chase, where’s Go?”

“I have a confession to make,” Chase said, voice low. “I have failed you.”

Kiriko, standing on Tomari’s other side, was more than close enough to hear the words, and Chase saw the color drain out of her cheeks. “He’s – he’s not -”

“I told him it wouldn’t be funny,” Go said from the doorway. He was breathing ostentatiously evenly, but a sheen of sweat dampened his hairline. Chase was sure he’d been running hard, before coming down the stairs. “But he insisted.”

“Oh, Chase is the one that thought it would be funny,” Kiriko said. She went from almost paper-white to flushed red within the span it took Chase to take a single breath. “Really.”

“Okay, okay, you got me.” Go held up his hands as if in surrender and shot a weighted glance toward Chase. “Sorry. Sorry I dragged you into it, Chase, but you don’t hold it against me, right?”

If Chase had interpreted Go’s expression correctly, the expected course of action was for Chase to back up Go’s story and thereby conceal Go’s absence from the Drive Pit along with Chase’s dereliction of his own duty. Chase wouldn’t have expected such dishonesty from Go, not even knowing that Go led a double life as Kamen Rider Mach and had to lie to maintain a secret identity. It wasn’t the same, when Go seemed to be asking him to lie to his friends and teammates. Chase turned back to Tomari.

“As I said,” he repeated. “I have failed you.”

“I don’t think you want to say that, Mashin Chaser.” Go lifted his chin as he spoke, shoulders settling into an unfamiliar slope. If Chase hadn’t been able to see his face, he would have said it was a stranger.

“Sorry, what’s going on?” Tomari glanced between the two of them. “Go, what’s wrong with you?”

“That isn’t Go.” Kiriko shifted her weight, and Chase was suddenly aware of her feet and their weighted boots. “I don’t know what’s going on, but that’s not my brother.”

“No,” Go said, and hesitated. Expressions flashed across his face too quickly for Chase to read, all of them cold, until he settled on an imperious arrogance. “My son is indisposed at the moment,” he said deliberately.

“Banno?” Kiriko said, incredulous, drowning out Tomari’s quieter exclamation of “Son?”

“Destroy him,” Krim said, speaking over them both. “He cannot be allowed to roam free.”

“We’re going to have a problem with that,” Go said.

_Not Go_ , Chase reminded himself. _Banno Tenjuro._ It made it a little easier to slip behind Banno and pin his arms behind his body. “I require instruction, Tomari Shinnosuke,” he said. Banno’s struggles were ineffectual, Go’s body on its knees. If he moved the wrong way, his shoulders would dislocate.

“No one is killing anyone,” Tomari said, and Chase gave him a faintly offended look for the unnecessary statement. “Chase, you’ve been watching him, right? We’ll confine him until we can figure out how to get Go back.”

“I have not,” Chase said, and started to explain the situation with the driving classes.

“This is all very well and good,” Banno interrupted him. “But I don’t think you want me locked up in a cell, either, where I can’t help you.”

“What are you talking about?” Tomari crouched down in front of him, putting them both on the same level.

“He cannot be trusted!” Krim snapped. “Whatever he says is a manipulative lie with just enough truth to sound plausible.”

“Mr. Belt,” Tomari said, and Chase couldn’t read his tone. Tomari wheeled a chair over and Chase maneuvered Banno into it. Despite his earlier attempts to break free, Banno was fully cooperative with the process of being bound to the chair, and Chase didn’t trust it. He hovered off to the side, after Tomari waved him away, close enough to see Banno’s hands behind the chair and his face as he spoke.

“Angel,” Banno said. “Otherwise known as Roidmude 099.” He gave a tight smile. “If you’re going to ask why you should worry about a Roidmude, when you’ve already defeated so many, please. Go ahead.”

With a pained expression, Tomari opened his mouth.

“It doesn’t matter,” Krim said furiously.

“Oh, but it does.” Banno smirked, and it was so unlike Go’s cocky smile that Chase felt pain in his chest.

“099,” Kyu said, and Chase glanced over. He’d cleared off a section of the whiteboard and written _099_ at the end of a list consisting of _006, 008,_ and _Banno Tenjuro._ “What?” he said.

“Why are they in numerical order?” Chase asked.

“That’s not the point.” Tomari gripped the Driver with one hand. “Mr. Belt, we should at least listen to what he has to say. If there’s another threat,” he waved his hand at Kyu’s list, “I need to know about it. We need to know.”

“Thank you,” Banno said, and Tomari grimaced in the same way Chase had seen him perform after he’d accidentally bitten into a lemon. He stood abruptly and stalked halfway across the room. Banno smiled blandly at Tomari’s retreating back. “As I was saying.” He glanced at Chase. “There is an object in my right pocket. I would retrieve it, but at the moment I am indisposed.”

Chase drew a glistening object out from inside Go’s jacket and retreated out of arm’s length. It glittered oddly under the lights of the Drive Pit, long and slender, and it took Chase a moment to place the shape. It was a stylized metallic feather, the grooves between the barbs not indentations at all but arising from the delicate lines of hundreds of circuits.

“099 is a danger to us all,” Banno said, voice silky.

“099?” Tomari repeated, and Chase shook his head. He wasn’t familiar with any of the particulars of the Roidmude assigned that number.

Banno gave a condescending smirk. “She wasn’t a significant player until she achieved the Ultimate Evolution.”

“It doesn’t matter,” Krim interrupted. “No Roidmude is enough of a threat to justify cooperating with _you_.”

“I wouldn’t be so sure about that,” Banno said. “She controls the will of others, and if she coopts 001, none of us will be able to stand against her.”

“You want us to rescue Freeze,” Kiriko said flatly.

Banno smiled with his borrowed face. “Precisely.”


	8. Amplifying Chaos

The reception hall was gorgeous from the outside, ostentatious in its use of wide open spaces. Walls apparently composed primarily of windows glittered in the sunlight, displaying no hint of a reasonable expectation of defensibility. The trees around it hindered visibility into the interior, but Kiriko was able to follow Shinnosuke and the rest of the team nearly to within arm’s reach of the building without being noticed from the inside.

“Why here?” Otta muttered from next to Kiriko.

“Aesthetics,” Banno said, crouched on her other side. He was clumsy, one knee planted awkwardly in the dirt, and Kiriko winced at yet another unwanted reminder that her brother’s body had been hijacked. A distant part of her mind wanted to scold Banno for getting Go’s pants dirty, and she recognized it as a futile attempt to take control of a situation she couldn’t even influence. Kiriko pushed it down.

In theory, 008 was in the hall, with one or more of his kidnapped victims. It wasn’t the church he’d mentioned in the interview, but Krim had pointed out that 008 wasn’t likely to stash his victims in the location he would have picked to fulfill his dream. He’d made a face Kiriko had never seen before, profoundly unhappy to be agreeing with Banno in the slightest. Tomari pulled a pair of Shift Cars out of his pocket, sending them off with whispered instructions; he didn’t want to go in blind, not without Mach acting as backup, and Kiriko had appreciated his uncharacteristic caution. Still, the entire situation grated at her.

“Are you sure we trust him?” Kiriko asked in an undertone. Tomari grimaced from Otta’s other side, eyes flicking down to his belt, and Kiriko could almost hear the conversation that had led them here in the first place replay in her mind.

_“Shinnosuke, this man is not to be trusted.”_

_Kiriko had never heard Krim sound quite so angry, but the rage was covering an undercurrent of fear. She couldn’t blame him; Banno had gotten him killed, after all, and was currently in possession of her brother’s body._

_“Of course he isn’t,” she said, before Tomari could say anything that might make the situation worse. “What have you done with my brother?”_

_“Ah.” Kiriko could almost see the wheels in Banno’s head turning in the split second it took for him to smile and answer. “I’ve been constructing a body,” he said. “When it is complete, I will be able to return my son to himself. Until then…” He trailed off and lifted Go’s shirt to show off a tracing of wire and circuit, part of it recognizable as distorted pieces of the Mach Driver, sunk into the skin around Go’s hips. Red angry lines radiated away from the machinery, but Banno showed no sign that he felt any pain. “This allows me to remain here.”_

_“I want to talk to him.” Kiriko lifted her chin, not looking at the damage done to her brother’s body despite the nausea climbing in her throat. She was intensely grateful when Banno dropped the shirt again, hiding the violation._

_“I’m afraid that would be.” Banno paused, making a show of searching for the right words. “Stressful,” he finished. “For the both of us. Unlike what Krim is capable of through the Drive System, this is an imperfect melding. Better if he remains asleep, shall we say.”_

_“You want me to just take your word for it?”_

_“Whether or not you believe me is irrelevant,” Banno snapped. “099 is the threat. She must be eliminated.”_

_“I suppose we’re supposed to take your word for that, too,” Tomari said, over the top of Krim’s protest. Krim subsided, displaying his neutral face. The display flickered erratically, and Kiriko put a soothing hand on the side of the belt._

_“I can tell you where 008 is based,” Banno said, with an air of suppressed smugness. “As a gesture of good faith.”_

_“Why?” Krim asked bluntly. “You can’t possibly believe it would lead us to trust you.”_

_“If you don’t trust me, at least believe that I do not wish to see humanity subjugated to the whims of the Roidmudes,” Banno said. “099 is able to control the others. She has already reached her Ultimate Evolution. If she is not stopped, Freeze and Heart will fall under her spell, and once she has conquered her compatriots, she will come for the rest of the world.”_

_“I don’t see how that’s any different from what Heart’s trying to do,” Tomari said._

_“You’re not listening,” Banno snapped. “She controls their will, and then she steals their Cores and saps their life essence. By that point, they go along with it, because she has promised them paradise. And all the while, she grows stronger.” He paused, glaring up at each of them in turn. “If she can’t reach Freeze, she’ll aim for Tornado. You need to kill him before she does.”_

“Doesn’t matter,” Tomari said, quietly, breaking Kiriko out of her thoughts. “We still need to stop Tornado from reaching Ultimate Evolution, and if he’s here, it’s worth it.”

“Or it’s a trap,” Otta said.

“You know I can hear you, right.” Banno glanced up and down the line, from Kiriko to Otta, then Tomari and Chase. “You’re less than a meter away, and you’re not whispering.”

“Oh, shut up,” Tomari said, before Krim could start in again. His hand was clamped over the driver, covering Krim’s digital face. There was no way it blocked Krim from speaking, but Kiriko could hear muffled noises from the Driver’s speakers anyway. “He’s not in there,” he added, as the two Shift Cars raced back. “But the kidnapped women are.”

“Then we at least get them out. Lt. Otta, you’re with me, then.” Kiriko stood, dusting off her hands. “And Banno. We’ll go in the side door, there.”

“Chase, watch from the other side.” Tomari gestured, and Chase took off at a run. “If 008 comes in the front door, I’ll keep him busy.” He gave Kiriko an awkward smile.

“Understood,” Kiriko said, and then they were moving. Banno kept up without comment, but Kiriko wasn’t about to look a gift horse in the mouth.

The interior of the hall was sunken into the ground, the access door on the second level of the structure, and Kiriko ran down the stairs. White gauze adorned the handrails, gathered in bows and knots as if 008 had started decorating for a wedding and then moved on to the glistening confetti sprinkled liberally over the floor before finishing the first project. The women were arranged around a central column, laid out on low cots spread with the same gauze. Kiriko couldn’t tell if they were alive from a distance; none of them were moving.

Despite being below ground, the space was brightly lit with natural light. The scent of rose petals wafted upwards as Kiriko ran, mixed with the confetti and crushed beneath her boots. Her palms itched with the desire for a weapon; there were too many spaces between the multitude of columns supporting the multi-story ceiling where 008 could be hiding, but she had to trust that the Shift Cars had done their work. She reached the first victim, noting the slow rise and fall of her chest with relief.

“This one’s alive,” she said, and Otta had reached the second.

“Her too,” he said.

All four women were breathing, but none of them were easy to wake. Kiriko chivvied two of them to their feet, swaying and leaning on each other, and up the stairs. Banno helped Otta with the last two, the seven of them emerging into the sunlight with Kiriko’s nerves screaming taut. It wasn’t far to the van, but Kiriko couldn’t breathe properly until the last of the women was buckling her seatbelt with clumsy hands. Otta was already in the driver’s seat, turning the key to start the engine, and Kiriko thought that for once a plan might be pulled off without a hitch. She turned to Banno to tell him to get in the back, but a sharp rumble from the ground shook her off balance.

A wordless roar of rage resolved itself into a whirlwind, throwing dust into the air. Kiriko staggered back, elbow banging painfully against the side of the van, and the Roidmude hit the ground with a deafening crash. The vehicle vibrated against her back; Otta had gotten it running. Kiriko yanked the door closed, stepping away and dragging Banno with her.

“Go,” she shouted at Otta, and to his credit, he followed directions admirably. The van peeled away, hostages safe for the moment.

“What the fuck,” Banno hissed in her ear, but Kiriko had heard Shinnosuke calling out his transformation catchphrase in the wake of Tornado’s landing. Drive barreled into the Roidmude from behind, knocking it off its feet.

“Get to safety!” Drive shouted. Tornado was picking itself up already, and Kiriko didn’t need to be told twice. She grabbed Banno by the wrist and started to pull him away.

The road ahead was blocked.

A woman stood in the way, eyes covered by dark glasses. Her arms were folded across her chest, legs bare beneath a knee-length trenchcoat, and her feet were planted firmly on the ground. Kiriko thought fleetingly that she should have looked far more precarious balancing on a pair of ten centimeter stiletto heels, but the woman was walking toward them with an exquisite sense of balance. She let her arms fall to her side, a metallic feather glinting in one hand. “Get out of my way,” she said.

“You’re not human,” Kiriko said in reply.

The woman paused. “And you’re not my concern,” she said. “Run, now, while I’m feeling generous.”

“Kiriko,” Banno hissed, barely audible over the sound of the struggle behind them. Drive and Chaser had their hands full with Tornado; they wouldn’t be able to assist.

Kiriko planted herself in the center of the road. “I’m not going anywhere,” she said.

“Little girl, do you know who I am?” The Roidmude smiled, reaching up to pull off her sunglasses. Her eyes glinted gold, the engraved circuits visible even from a distance.

“099,” Kiriko said, and Banno groaned.

“Stop trying to antagonize it,” he whispered harshly. Kiriko ignored him; she had to distract it until Drive and Chaser took care of 008. There was no way they could handle both of them together.

“You can call me Angel.” The Roidmude paused. “At least, until I get tired of you.” Her silhouette rippled, stretching out into gold and white. Shimmering wings fell from her shoulders, skin hardening into armor plated in dark red and marbled white. A thorned halo spread around the smooth paleness of her head, the ends tilted downward to angle in front of her blank eyes instead of making a full circle. The effect was eerie, its attempt at beauty overwhelmed by an eldritch aura. It sent shudders over Kiriko’s skin. “I warned you,” the Roidmude said, its stiff features barely moving.

The halo gleamed, blurring and doubling. Kiriko couldn’t look at it; the light made her eyes water. She heard rather than saw the projectile speeding toward her, feeling the air displace against her skin. She was already moving, shoving Banno out of the way with one hand and flinging herself to the other side. The projectile passed closely enough to graze Kiriko’s cheek, and she saw strands of her hair flutter to the ground. It was a duplicate of Angel’s halo, wicked points glinting as it vibrated in mid-air.

A choking noise caught her attention, and Kiriko looked to the side. The second halo was spinning in Banno’s chest, out of phase with Go’s flesh and crackling with energy. It edged free just as Kiriko took in the sight, and Banno went from rigid to boneless as it cleared his skin. He dropped heavily to the ground, making no effort to break his fall, and Kiriko barely managed to catch him. He stared up at her, blinking slowly.

“Huh,” Angel said, looking at the halo. A fitful gleam flickered in its center. Angel gestured, and it dissolved. “I will come for you,” she said, staring at Kiriko, and took off toward the battleground.

“Tomari, look out!” Kiriko screamed, but it was too late. 099 was already in the thick of the fight.

* * *

The waves moved sluggishly, tiny fingers of liquid with barely enough momentum to reach farther up the misshapen sand. A thick crust lined the edge of the water, white bright enough to hurt against the gunmetal gray of the waves. The sky was no better, colorless and brilliant, the light so diffuse that he cast no shadow. The sand was as colorless as the water, both fading into mist. Or nothing. A sense of tranquility sat heavy in the air, faint knowledge that nothing had ever changed here and nothing ever would. It should have made his skin crawl, but he didn’t mind.

A crunching sound startled him, and Go spun around to see a blurry shadow approach. Its footsteps were visible in the frozen white froth, as if it were avoiding both land and sea. He couldn’t make out its face, even when it came within arm’s reach of him. Go narrowed his eyes against the overbrightness of the sun that wasn’t there, trying to get a better look. It didn’t help. He might as well have been wrapped in gauze, ears stuffed with cotton, one step removed from what he could see and hear.

“Go.”

There was an edge of familiarity in the voice, and Go opened his mouth to ask who the man – he thought it was a man – was, but before he could speak, it clicked in his subconscious and he knew who was standing in front of him. “Professor Banno,” he said.

“Cold words, for your father,” said Banno.

Go closed his mouth with a snap, too many words trying to rush out and he couldn’t say any of them. “Why?” he asked.

“Why, what?” Banno’s face was a little clearer, now, looking more like the pictures Go had wanted to see when he was still small enough to sit on his sister’s lap and listen to her tell stories.

“Why did you leave? Why did you create the Roidmudes? Why did you do any of it?” Go flung his hands out wide, pointing at everything and nothing.

“I knew you wouldn’t understand,” Banno told him. “You take after your mother.”

The gray world around him tinged itself with red, its pervading atmosphere of peace starting to boil away, and a jagged gold crack split the sky. “What did you say?”

“Your sister was bad enough,” Banno said, advancing toward him. The split widened, its edges weeping nothing, and Banno’s voice took on a frantic edge. “But you – I knew you would be nothing but a disappointment.”

“Don’t talk about my sister like that.” His hand had curled itself into a fist, entirely without his permission, as if the sky had prodded it into action. Go looked at it and decided that it was already there and might as well be used. He smashed it into Banno’s jaw, stumbling as Banno flickered like smoke and his hand just slid through the air.

“It’s the truth,” Banno said, sounding more sure of himself. “I had high hopes for her, although she wasn’t the son I deserved, and all she did was one disappointment after the next. But you – you were even worse. Couldn’t follow the simplest directions.”

“You left before I grew up!” Go retorted. “You didn’t give me a chance!”

“I left because there was no point in staying around for either one of you.” Banno’s face was almost perfectly clear, now, set in arrogant, dismissive lines. He took a step closer, but his edges were wavering into translucence. “Even now. Now that you’re an _adult_.”

Go could almost see the scorn dripping off the word, feel the sarcasm rippling through the air, and the energy that had come with rage was starting to drain away into the gold-edged void. It should bother him, he thought, but there was no urgency in it.

“You still haven’t figured it out.” Banno chuckled, without so much as a hint of amusement in the sound. “Kiriko would have gotten it by now. But not you. How that idiot Harley looked at you and thought you were an appropriate operator for the Mach Driver…” He paused, leaning back. “Then again, the Mach Driver is a pitiful shadow of the Drive System. Which is to be expected from a hack like him.”

“You didn’t create the Drive System,” Go retorted, trying and failing to hold onto the sense of indignation, anger, anything more than the deceptive calm of the barely-moving waves under the disappearing sky. “Krim Steinbelt did that.”

“Please.” Banno waved a dismissive hand. “We all know it was my work that formed the basis of everything he did.”

“Whatever.” Go poked at Banno again, but his fingers slid through the insubstantial shadow. It felt greasy, somehow, as if it were clinging to his skin when he withdrew. He tried to rub it off, but it still felt sticky. His memories were jumbled, when he tried to figure out where he’d been before he’d been standing on the beach, or how he’d gotten there. “Wait, what do you mean, figured it out?”

There was a belt, heavy around his waist, the shape of the Driver under his hands exactly where he would have expected it to be, but the Signal Bikes were missing. The Driver cracked under his touch, spiderweb-shapes racing along its surface, and Go suddenly knew what had happened to it. The tablet holding Banno’s subroutines had destroyed it.

“It was you,” he said, and some of the tranquility faded anew. He was proud of how well he handled the Driver, how far he’d gotten in his training, how much he’d done with it, and Banno had ruined it. “You destroyed my Driver.”

“Can you never look beneath the surface?” Banno snapped.

“Can’t you just say what the hell you mean?” Go retorted, hands curling into fists again. The anger felt good, giving him a rush of heady strength. Heat prickled over his palm, flaring into pain, and he looked down to see a bruise-like mark. Virulent red and poisonous blue, edged starkly against his skin, and it beat in time with his heart.

“What is _that_?” Banno stared at him, looking between his face and his hands.

Go didn’t have an answer; the memory was just out of reach. It wasn’t something he needed to explain to Banno. He balled his hand right back into a fist, feeling the incandescence pouring out of the mark, and swung at his father’s smug face for the second time. This time, it connected. Banno went sprawling, and Go leapt on top of him and hit him again. And again. And again, until Banno stopped protesting and the shadow-substance faded away.

The belt still settled around his hips cracked further, melting into smoke and dissipating. The beach started to shake beneath his feet, and Go began to run. He didn’t know where he was going, only that he had to escape. He couldn’t run away from the water, and it burned his flesh when the waves splashed higher. The shaking grew worse, and the ground started to open almost beneath his feet in a time-delayed mirror of the empty sky. He leapt over the chasm, barely reaching the other side and landing on his hands and knees. The water hissed over the mark on his palm, washing it clean and leaving burned skin in its wake. Go cried out, cradling his hand to his chest, but the water splashed toward him again. Go pulled himself to his feet and kept running.

 _You should have taken what I offered_ , he heard faintly in Banno’s voice.

“You didn’t offer me anything,” Go shouted, and then his foot came down on nothing at all. He pitched forward, falling, the wind whipping past his face until he burned with cold. He had just enough time to wonder if he would fall forever before the ground he couldn’t see met him with a jarring thud and knocked the air out of his lungs.

It took him a long moment to unlock his chest, and the sense of relief that came when he finally took a shuddering breath washed all the strength out of his limbs. He didn’t care, for a moment, content to simply breathe before it occurred to him that he’d landed somewhere dark. He couldn’t see at all, until he tried to blink and realized that his eyes were closed. He opened them.

A staircase rose above him on one side, institutional linoleum that was somehow depressing in its banality. The steps were closer to his face than they should have been, until he sat up and shook his arm experimentally. It seemed no worse for the wear for having landed on the edge of the bottom step, but he was sure there hadn’t been stairs there a moment ago.

“Banno?”

The voice on his other side startled him badly, and he scrambled backwards only to run straight into a wall. It hit his spine and the back of his head and he flinched. He hadn’t been moving fast enough to hurt much, but the shock cleared his vision and his thoughts. Someone else was in the stairwell with him, and before he could say anything, a door slid open and a man in a suit came rushing out.

“I heard a noise,” he said, and his eyes widened. “What happened?”

The woman who had been in the stairwell with him knelt down and tried to help him up, concern written across her face. He batted her hands aside, climbing to his feet with a lingering sense of disorientation. The thought came that she would try to hurt him, for his own good, if he wasn’t careful and he had no idea why.

“I’m okay,” he said, because she was giving him a look that clearly said she was expecting some kind of answer. The man in the suit and tie followed her hesitantly. His suit jacket was oddly patterned, flashy despite being entirely constructed out of shades of gray, and he immediately liked it. The feeling of affinity warred with a strong sense of wariness, as if the man was someone he shouldn’t trust. Someone who would try – had already tried – to hurt him. A brief memory of falling hard into water brushed past him, gone before he could examine it.

“What happened?” the man asked again, and all he could do was shrug. He had no idea how he’d ended up at the bottom of a flight of stairs. A dull ache spread over his lower abdomen, and he shifted his weight to relieve it. It didn’t help.

“He just,” said the woman, and made a vague gesture.

“I was talking,” he said, but he couldn’t bring the face of the other person to mind. There had been water and sand, and then it had all fallen apart. The images were blurred, fading as he tried to recall them. “And then I fell.” That wasn’t right. “I ran,” he corrected himself. “And then I fell.”

“You weren’t running,” the woman said, sounding absolutely sure of herself, and it cast doubt on the memories of fleeing from the shaking ground. “Are you all right? You did go down pretty hard, after Angel threw that thing at you.”

He could only stare at her, unable to bring up any memory of the event she was referencing.

“I’m not worried about _you_ ,” the woman said impatiently. “I’m worried that you got my brother hurt. You might be my father, but I won’t forgive you if something happens to Go.”

The name echoed along his skull. It meant something. He opened his mouth to ask, finally, and the door slid open instead. It was another man, with a pretty face and disheveled hair, purple jacket hanging open. His eyes were another shade of purple, paler than the jacket, and there was a bruise along his jaw. “Rinna has asked me to tell all of you to come inside,” he said, and his voice echoed.

“Are you sure you’re all right?” the woman asked.

He hadn’t realized that the choked-off whimper that had come after the second man had spoken had come from him; there was a teetering sense of instability inside his head, blocks poised to fall, and he didn’t know what they were made of. “I don’t know,” he said, because it was the truth. It didn’t matter if he trusted any of them or not.

“Go?” said the second man, and that was wrong. He wasn’t a man. He had been created, but he had a name.

“I saw you,” Go said helplessly. “In… in…” Bile choked off his throat as the image swept over him.

_Chase was restrained, on a table in a small room at the end of a hallway Go hadn’t even known was there. How many times had he been in the basement and never noticed it, he’d thought, but it explained why the proportions were so wonky, why walls that shouldn’t have been where they were had cut other rooms smaller than he’d expected. He hadn’t seen this coming, hadn’t thought he would find the traitor caught and restrained, still alive._

_“What are you doing here?” he asked._

_“We need to leave,” Chase said. “Heart has been lying to you.”_

_“He wouldn’t,” Go objected, but there was a yawning pit in his stomach that told him otherwise. “He – he couldn’t.”_

_“Release me before they come.” Chase stared at him, pleading and hopeless, and Go backed through the door. “Before Freeze alters your memory again.”_

_“What do you mean, again?” Go demanded._

The memory ended with blue-white light overwhelming his eyes. Go caught himself on the doorframe, breathing hard. Chase reached for him, and Go froze. Half of his instincts were screaming at him to defend himself against the Roidmude traitor and the other half wanted to throw himself at Chase, and he couldn’t do either. Memory hit.

_There was another corridor, in the basement. Go laughed, because it explained why the layout was so screwed up. It was missing space, and he didn’t know how he hadn’t noticed it before. The laughter died out before long, and he glanced nervously over his shoulder. There was a reason he shouldn’t go down the new hallway, but he couldn’t remember what it was. Shrugging, he moved across the cracked concrete floor._

_Most of the doors were locked, dark on the other side. Go picked one of the locks, just out of curiosity, and because it was a cheap lock that did its job so poorly it deserved to be opened without a key. The room beyond it was nothing more than empty, dusty shelves. Go made a face at it. “Why are you even locked, then,” he muttered._

_The last door was different; same lock, but there was light coming under the wide crack at the bottom of the door. Go rubbed his hands and looked at it for a moment. Nothing moved. He thought about tapping on the door, decided against it, and poked at the lock. It opened easily._

_“Chase,” Go said involuntarily. The Roidmude traitor, alive and restrained, stared back at him with consternation. He shouldn’t have been there; Heart should have killed him when he’d had the chance, not brought him back for – Go’s stomach turned. Chase’s pale skin was bruised, in more places than one, and a cut along one wrist was bleeding sluggishly. “Are they torturing you?” he asked sharply._

_“You have to go,” Chase said. “Before Freeze finds you down here.”_

_“He won’t hurt me,” Go said absently. “Heart wouldn’t let him.” Even if Freeze gave him the heebie jeebies, he trusted Heart absolutely. He circled around the table where Chase was restrained. “Why are you still alive?”_

_“You know why,” Chase said. The corner of his mouth was bloody, too. “You have to go,” he said again. “If Freeze continues to rewrite your memory –“_

_“Continues?” Go interrupted, and the door slammed open. Blue-white light washed the room away._

Chase’s leather jacket filled his vision. He was leaning on it, grateful for the strength and solidity holding him up. “I don’t,” he said, but he didn’t know what he wanted to say. The walls around him were spinning and changing shape. “How many times?”

“Too many,” Chase said, and another wave broke over him.

_Too many inconsistencies, Go thought, shrugging out of his hoodie. It was dusty and smudged with dirt, but the pleasant burn in his limbs was enough that he didn’t care about having to bleach it again. Heart had wanted him to fight without the armor, to train until it became second nature. Go didn’t argue, although not practicing use of the weapons that came with the armor didn’t make sense to him. It was fun, anyway._

_The little machine was mostly full; Go added the soap and closed the lid and frowned at the almost imperceptible hesitation before the machine shuddered to life. He stretched, not wanting to go back to his room, but not wanting to join Heart and the others either. Which was what had led him to the previous thought. “It doesn’t add up,” he murmured._

_The space in the basement was wrong. The room he slept in was wrong. The way Medic and Brain looked at him when they thought he wasn’t paying attention was wrong. None of it felt like he’d been part of their team for as long as Heart assured him he had; Medic, in particular, looked at him as though she wanted to eat him. Brain just had an expression that said he was staring at an insect crawling across a formerly-clean floor._

_“Gotta be hiding something,” Go said softly. In his experience, the basement was usually a pretty good place to go looking for secrets. Even if this one so far had nothing but dusty rooms and a barely-functioning washing machine, it was still better than pretending he didn’t notice how his teammates stared at him._

_The corridor down the east side of the building took Go by surprise, despite his actively having searched for it. He went back and forth a few times, looking at the room hiding the entrance from the outside and rebuilding the map in his head. Some of the inconsistencies resolved themselves, the maze much less of a maze now that he knew how parts of it were blocked off._

_“Son of a bitch,” he said, and went inside._

_Doors lined one side of the hall; since the other was where the rest of the basement lurked, Go wasn’t surprised. He poked at a few of them, but they were stuck mostly shut or apparently locked, and the few he did open had nothing interesting inside. No reason for the deliberate placement of what he was now sure were temporary walls. Or maybe not; he’d seen weirder buildings._

_It was the last door that caught his now-wandering attention. A pale glow spilled over the floor from under the badly fitted frame, implying that this room – unlike the rest – was actually in use. For a moment, Go hesitated. Freeze didn’t spend as much time upstairs with the rest of them; it was possible that this was his own personal space, and Go didn’t want to intrude. Freeze made him nervous; more than Brain, more than Medic._

_Then again, no one had ever accused Go of backing off. He knocked on the door, but the only sound that came from the other side was a choked-off gasp. He frowned. If that was Freeze – but it didn’t sound like Freeze – then something was wrong; if not, there was clearly another agenda at work. Go opened the door._

_Chase lay restrained on a table in the center of the room, mostly-empty shelves around him, harsh lighting accentuating the shadows and washing out his already pale skin. He raised his head just enough to see, when Go came inside, dropping it back down with a thud. “You,” he said. There were marks on his skin, cuts and bruises that looked as though they had been deliberately placed. Heart wouldn’t torture another person, Go thought, but he wasn’t prepared to say the same about Freeze. A sick feeling turned his stomach, and he grasped for something else to distract him._

_“You’re the traitor,” Go told him, and for a moment, he thought he saw despair flash across the other man’s face._

_“They’re lying to you,” Chase said. “I was trying to find you.”_

_“Heart wouldn’t,” Go began, but hadn’t he just been trying to reconcile all the little details that didn’t add up? He shook his head. Even if the Roidmudes hadn’t been telling him the whole truth, it didn’t mean that Chase could be trusted. He still wanted to believe Chase._

_“Freeze rewrote your memory,” Chase said, tugging at the restraints. “There’s a scar behind your ear. That’s the mark it leaves behind.”_

_Go touched the sore spot automatically. “Heart said,” he started._

_“Heart is_ lying _,” Chase broke in. “We have to leave. Now.”_

_A broken vial was on the shelf, next to a Shift Car Go didn’t recognize. “What’s that?” he asked. It looked new, unlike almost everything else in the room._

_“That was the antidote,” Chase said. “Go, your sister is worried about you. We need to leave before they find us.”_

_Indecision sat heavy in his throat, paralyzing him for a small eternity, and then Go shook his head. There was too much to explain that the Roidmudes had tried to gloss over. Even if he couldn’t trust Shin, he had to trust his sister. He started to unbuckle the restraints; traitor or no, Chase didn’t deserve to be tortured, and Go wasn’t about to kill him while he was helpless. Particularly not when he wasn’t sure if Chase was even a traitor, or if the Roidmudes really were trying to work towards peace instead of annihilation._

_“Thank you,” Chase said, but Go had to help him walk out the door._

_“You can say thank you by buying me coffee,” Go said without thinking about it._

_“Is that a human rule?” Chase asked, and Go choked on nothing._

_“Uh, sure,” he said. “Yes. Yes, it is.” And at some point he was going to have to explain to Chase that he had just asked him on a date, and that Chase had accepted. He didn’t think Chase was going to object._

_“I wish you hadn’t come down here.”_

_For a moment, Go thought Chase had spoken, but the voice was wrong. He looked up to see Heart barring the corridor, face set in compassionate regret. Go felt shame, for disappointing Heart, so strongly that it took him a moment to see Freeze standing behind him. The irritation rolling off of Freeze cut through Go’s feeling of guilt. “I wish you hadn’t been torturing someone in the basement,” he said, and made as it to walk around the two of them._

_It didn’t end well. The scuffle – it wasn’t really a fight, not when Go didn’t have the Mach Driver with him and Chase couldn’t stand on his own – left Go face down on the dusty concrete floor and Chase out of his line of sight._

_“I told you he was more trouble than he’s worth,” Freeze said, and Go’s blood went cold._

_“I knew something wasn’t right,” he said, struggling again. Freeze’s boot dug deeper into his spine, wrenching his shoulders farther back._

_“I’ll help you,” Chase said suddenly. “If you let him live, I’ll help you take down Drive.”_

_“Is that enough incentive?” Heart asked silkily, and the pressure on Go’s back vanished. Freeze hauled him to his feet, and blue-white light swamped his vision._

The flood of memory drained away, leaving him shaken and raw, but he knew who he was. He remembered who he had been, before the Roidmude had twisted his thoughts, and what it had done to him. Flashes of images still crowded him, flickering past his mind’s eye, but one in particular kept repeating itself. The echoes rang in his ears as his balance returned and he found Chase was still holding him up, arms still locked protectively around him. Go pushed him away.

“Are you all right?”

“You betrayed us,” Go said, and hurt flashed across the Roidmude’s face. “You told Heart that you’d help him take down Drive.”

“I was trying to save your life,” Chase said. “There was no other option.”

“Not trying to destroy humanity was the other option,” Go snapped. There was another half-seen memory lurking, the sense of being a prisoner in his own head, and he shoved it back down.

“Freeze would have killed you.” Chase reached for him again, and Go tried to avoid his touch. There was a wall in the way, jarring against his spine in a way that brought a sudden flash of Freeze’s boots grinding him into the floor. It brought the pain in his abdomen flaring to life again, sharp-edged this time, and he choked back a groan.

“Wait,” Kiriko said, and Go had honestly forgotten that Shin and his sister were there. “Where’s Banno?”

“You lost the tablet?” The pain evolved into a gnawing feeling in the pit of his stomach, the feeling that he’d forgotten something else re-establishing itself with a vengeance, and Kiriko’s face shifted subtly. She exchanged a glance with Shin that he absolutely did not like, and then Shin held out a hand.

“Come inside the Drive Pit,” he said.

“I don’t want to go anywhere with him,” Go said sullenly, but Kiriko was standing right next to Shin with a glint in her eye that said she wasn’t about to be disobeyed.

The door slid open without hesitation, the biometric locks apparently disabled, and Go couldn’t help giving the unassuming panel a dirty look as he passed it. A knot of apprehension had lodged itself in the his ribcage, but walking inside the Drive Pit was a relief. It was familiar and safe, even if he’d been locked in it without good cause, and some of the tension drained away.

“The feather circuit,” Rinna said, holding up a metallic object, and then her eyes narrowed. “What happened to Banno?”

“I have no idea how it happened,” Shin said. “But he’s gone. Go’s back.”

“He seemed fine after Angel stole 008’s Core and left,” Kiriko said. “Which is the only reason Shin came ahead at all. And then he tripped down the stairs, and now?” She gestured toward him.

“Maybe that weapon of hers did do something,” Shin said, and Go had the mental image of a pointed ring hovering in the air. Dull pain throbbed in his chest, radiating upward from the hurt lower down, and he rubbed it. It didn’t go away.

“She isn’t supposed to be able to affect humans, I thought,” came a voice Go was too tired to identify.

“Shinnosuke,” Krim said, and Go stopped paying attention. It was too exhausting, trying to keep track of who was saying what, and who he was supposed to be upset with and who he was supposed to trust. At least the ground underneath him was solid and stable, and wasn’t giving him any surprises, he thought, and was rudely disabused of the idea as the floor vanished without warning.

“What?” he said.

“Mad Doctor,” Kiriko told him, which wasn’t helpful at all.

“Sure. Whatever.” He was staring up at the ceiling, and Chase appeared in his field of vision. He was upside down, and then he put his hands on Go’s shoulders.

“This might hurt,” Kiriko said.

Hurt was an understatement. It was agony, sweeping over and through him, and Go writhed trying to get away from it. An implacable grip held him down at the shoulders and ankles, both comforting and suffocating. Go held onto it with both hands, not sure if he was trying to push it away or keep it from disappearing, until the pain finally receded.

The pressure had vanished, when he took a deep breath and looked around. His mind felt clear for the first time since they’d faced 001 in the bank, and it had attacked Kiriko. Go rubbed his eyes. His lashes were sticky, little particles crumbling against his fingertips, and he frowned. More important was the slowly settling sequence of events that had followed; 001 had altered his memory. He could see it now, knew that he’d spent some indeterminate amount of time in the Roidmude base, and that he’d found Chase. More than once.

The tablet containing Banno Tenjuro had crumbled, during their escape, and Go’s memory stopped. There were a few flashes, after that, but nothing clear. He could feel the tablet digging into his skin, and then he’d opened his eyes to the darkened Drive Pit ceiling.

“Are you awake?” Chase asked softly, and Go flinched. He hadn’t noticed Chase leaning on the wall almost behind him.

“Awake?” He rubbed his fingertips together again. “Was I asleep?” He pushed himself into a sitting position, muscles unaccountably stiff, and stretched.

“For a while.” Chase’s voice echoed around the Drive Pit, and Go looked around. No one else was there. “Your sister will return,” Chase said, and Go felt his shoulders tighten reflexively.

“That’s not -” he said, and then let the words trail off. Chase wasn’t looking directly at him, instead staring just past him with his face carefully blank. Go’s own voice echoed in his ears, an accusation of betrayal for which he had no context. He thought he might be able to guess. “I didn’t mean it,” he said.

“What?” Chase was looking at him now, faint confusion replacing the studied lack of expression.

“When I said you betrayed all of us.” It was hard to get the words out, around the stiffness in his throat. “I didn’t mean it. I’m sorry.”

“I have spoken with Shinnosuke at length,” Chase said. “About the assistance provided to 001 in exchange for your continued survival.”

“I’m trying to say thank you!” Go scrambled off the low couch, feet unsteady beneath him for the briefest of moments. Chase reached out as if to help, and Go knocked his hand aside without thinking about it.

“I don’t need your gratitude,” Chase said, and there was distress, buried underneath the indifference. “There is no longer a debt between us.”

It stung, hearing those words. Go opened his mouth to tell Chase exactly where he could take his declaration of fairness, but Chase had stepped closer and he couldn’t quite gather what he wanted to say.

“There is no imbalance,” Chase said softly. His hand rested feather-light against Go’s jaw as he shifted forward. “You cannot take advantage of obligation that does not exist.”

“What?” Go tried to say, but Chase’s mouth was on his and it suddenly didn’t matter.

The edge of the bench hit the back of one leg and then the other, and Go overbalanced. Chase fell with him, pulling back just before the moment of impact. He caught himself, impossibly graceful, his other hand still cupping Go’s face. Just as Go started to get his breath back, Chase slowly leaned down and Go nearly lost track of everything else. A thread of awareness struggled to hold on, telling him even as he kissed Chase hungrily, almost desperately, that here and now weren’t right. Pulling himself away was one of the hardest things Go had ever done.

“Wait,” Go said, and Chase pulled back.

“Is something wrong?” he asked.

“Wro- no, not wrong.” Go nudged him until Chase was no longer lying on top of him. “Definitely not wrong.”

“Then why did you stop?”

“What did you mean, take advantage?” Go asked instead of answering the question. The Drive Pit wasn’t the place for intimacy, he reminded himself, not when the door didn’t lock and an entire team of over-invested workaholic lunatics might wander in at any time. Despite his determination not to be an exhibitionist in this one small thing, Chase was making it extremely difficult to keep anything else in mind. Go couldn’t stop running his thumb back and forth over their interlocked fingers, brushing across skin against skin with a delicious shivery sensation. It would build, if he let it, and he almost regretted trying to stop.

“I spoke with Kiriko,” Chase said, and the thought of Go’s sister thoroughly doused any budding sense of heat.

“You did what,” Go said. Chase wouldn’t let go of his hand, and he sulkily leaned back against the other man. “That’s not how this is supposed to work.”

“Have I broken a human rule?”

Go couldn’t see Chase’s expression as long as his face was pressed against Chase’s shoulder, but the thread of anxiety in his voice was clear enough. “Yes?” he said, his tone lilting up at the end despite himself. “You’re not – you don’t ask a guy’s sister about this kind of thing.”

“I asked her why you didn’t want to create a friendship,” Chase said. “She told me that you might feel I was acting out of obligation, and not want to take advantage of me.”

“That,” Go said, and paused. “Sounds very much like my sister,” he added, when Chase started to tense up underneath him.

“You would not have been taking advantage of me,” Chase said, voice small. “I thought I was clear, about my interest, but you ignored it.”

“It’s – it’s complicated,” Go said. “Really complicated.”

“Because I am a Roidmude,” Chase said, and Go had honestly almost forgotten that his friend wasn’t human.

“No,” he said. “That doesn’t matter anymore.” It was even mostly true; that Chase wasn’t technically human was a part of him that Go didn’t have to think about. Not when Chase fit against him so perfectly, soft skin and solid strength, no hint that he could be anything else.

“Then what?”

Chase might have been frustrated, with that edge to his voice, and not knowing what Chase really felt and what was just an act wasn’t helping. Go squeezed his eyes shut briefly and pressed himself closer. “Can we not talk about this now?”

Chase was silent for a moment, almost long enough that Go thought it was agreement by lack of dissent. “Then when is the appropriate time?” he asked.

“When we’re done with 001 and Heart,” Go said. “When we don’t have to worry about 099. We’ll talk about it then.” Another thought occurred to him. “We can’t tell anyone else about us until then,” he added. “Not until I can explain things.”

“This is a human rule?” Chase sounded dubious for the first time when trying to figure out social etiquette, and Go squashed his sense of misgiving that he was – after clearing up a misunderstanding about what didn’t count as exploiting a power imbalance – taking advantage of Chase’s lack of familiarity with appropriate behavior.

“Kind of,” he said, the words shifting in his mouth. “Kind of not – I’m asking, okay?”

“It’s important to you,” Chase said finally, the inflection not quite enough to make it a question.

“It’s really important,” Go answered. “It’s – yeah.”

“I am supposed to report to Tomari Shinnosuke and your sister when you’re awake,” Chase said, after a long enough pause that Go was starting to drift back into a half-sleep.

“Shin got us away from Freeze and Heart, then?” Go asked idly, not expecting anything other than an answer to the affirmative.

“Er,” Chase said.

“What?” Go pushed himself upright, glaring down Chase. His face was only half visible in the dim light, but he looked apprehensive. “What?” Go said again.

“Some time has passed, since then.”

“Time,” Go said flatly.

“Kiriko should explain this to you,” Chase said, and if Go hadn’t known better, he would have said Chase sounded nervous as well as looked it.

“ _You_ tell me,” he said, but he wasn’t entirely willing to accept Chase’s hesitant explanation that Banno had somehow managed to possess his body by worming his way into the Mach Driver and melding it into Go’s skin.

“There are scars,” Chase said, and carefully reached. Go followed his guide, feeling the ridged numbness across his lower abdomen, where he should have had nothing but smooth skin.

“Nope,” he said, and tugged his shirt back down.

“I am not lying,” Chase said, and Go shook his head.

“I can’t think about this right now.” He climbed off the bench. “You and me, that’s a thing. The Roidmudes, that’s another thing. I don’t have space for a third thing.” It felt good to stretch and move, and he put thoughts of Banno’s violation aside. His skin crawled, nausea roiling in his stomach, and he snatched his hand away from the marred skin. “You said it was a couple of weeks. I need to know what’s going on.”

“Go,” Chase said. He was standing, but the trace of uncertainty Go could see in his posture was fading. He nearly broadcast the idea that Go would know what he needed to do to handle his own emotions and that Chase should follow his lead. “Very well.”

The discussion migrated to the driving school’s cafeteria and its bottomless supply of terrible coffee; no one was around to actually make the coffee, but it didn’t exactly require rocket science to figure out. By the time Kiriko and Shin entered the SIU’s office, Go was waiting. Coffee was on both of their desks, long gone cold, but he figured it was the thought that counted.

“You were supposed to call me,” Kiriko said to Chase.

“It was like, three in the morning,” Go said. “You didn’t need to be woken up. You get cranky.”

“I’m your older sister,” Kiriko said. She grimaced at the coffee.

“He already told me everything,” Go said. “How long will it take Rinna to rebuild my belt?” Shin suppressed a guilty start, and Go ran up to him. “She already did, right? Right? Where is it?”

“Uh,” Shin said, looking over at Kiriko.

“Hey, I’m over here,” Go said.

“I don’t think –“ Kiriko hedged.

“Look.” Go crossed his arms and leaned forward. “If this 099 took out 008 as easily as Chase said she did, you need my help. You can’t deal with her and Heart and Freeze all at the same time, and you can’t let them take each other out, either.”

“Tomari,” Kiriko said, and Shin sighed.

“He’s not wrong,” he said, and opened his desk drawer. A shiny new Mach Driver was in it, none of the nicks or scuffs Go’s original Driver had accumulated over the months he’d used it. His Signal Bikes poured out of the drawer after it, racing little circles around the floor.

“You follow my lead,” Shin said, holding the Driver just out of reach.

“Yeah, yeah.” Go made another grab for it. “I won’t do anything stupid.”

“Now that really would be asking too much,” Shin said, and Go didn’t quite register the words until he’d gotten the Driver back.

“Hey!”

“We’ll let you know when Tomari needs your help,” Kiriko said. “For right now, let me drive you home.”

“Chase can take me,” Go said. “Since he’s apparently living in my apartment now.”

“Let me drive you,” Kiriko repeated. “Chase can follow on the Ride Macher.”

“Of course,” Chase said, and vanished out the door. Go glared at the empty doorframe.

“Traitor,” he muttered under his breath. This had all of the hallmarks of Kiriko wanting to have an uncomfortable conversation, and he wasn’t ready for it.

Despite Go’s misgivings, Kiriko was silent during most of the short trip. It wasn’t until she put the van in park in front of Go’s building that she took a deep breath and turned to face him. “Why didn’t you tell me about Chase?” she asked.

“How did you _know_?” Go blurted out. There was no way she could, and yet somehow she’d figured out that the two of them were – involved.

“He was in your apartment and he _told_ me,” Kiriko said tartly. “And before you say anything, of course I asked why he showed up alive after we saw him die.”

“After – what?” Go blinked, and the context surrounding Kiriko’s question rearranged itself in his head with stunning speed. “You’re talking about when I saved his life.”

“Of course I am.” Kiriko’s eyes narrowed. “Why, what did you think I was talking about?”

“The same thing?” Go hazarded, and Kiriko sighed.

“You don’t _trust_ me,” she said. “And I don’t know what I did to merit that, but I want to fix it.” She twisted her hands in her lap. “It’s just you and me, Go. We’re the only family we have.”

“It was just.” Go couldn’t meet her eyes; he looked down at his own hands. “You’re upset I didn’t tell you about Banno, either,” he said, and Kiriko sighed again.

“I was trying not to dump everything on you at once,” she said. “I know you wanted to protect me, but I’m your older sister. I’m an adult, Go. You can’t make decisions for me like that.”

“I just.” There was moisture at the edge of one eye, and Go looked up, trying to keep it where it was. “I didn’t – I wanted you to not have to take care of me, for once. I wanted you to not have to worry about something. You were always the one protecting me.”

“Oh, Go.” Kiriko took his hand. “You know what I remember? You working so hard to be strong, so that I wouldn’t have to worry. All the time.”

That wasn’t how Go remembered it at all. “But,” he said.

“We can both look out for each other,” Kiriko said, gently. “Okay?”

It was on the tip of his tongue to tell her about Chase, but he couldn’t do it. He couldn’t put something else on her, not when she was looking at him with a bright and hopeful expression. “Okay,” he said.

“Good.” Kiriko released his hand and patted it. “Now go inside. Get some rest. Go for a run. When we find one of them, we’ll let you and Chase know.”

Go nodded again, and climbed out of the van. _When the time is right. That’s when I’ll tell her._


End file.
